I am planning a year-long journey beginning next year - sort of a celebration of mid-life, reaching my early retirement milestone, and venturing into business on my own (which will not happen until I get back, obviously!).

I currently have plans to visit, in no particular order:
Cambodia
S. Korea
China
Vietnam
Thailand
Indonesia
Australia
India
S. Africa
Tanzania
Kenya
Dubai
Greece
Turkey
Egypt
Croatia
Morocco
Ethiopia

And a bunch of EU/Shengen zones.

This will be my first visit to most of these places. Anyone know of a good resource that can me help acquire visas? I do not have the time right now unfortunately to run around to all the consulates, do it on my own, etc. My first outbound flight is April 17 to Singapore, so I have some time although there are other int'l trips before then for which I will need my passport.

Also interested in specific travel advice for these places - that which MUST be done or avoided. I am a professional photographer by trade so ideas for what might make interesting photographic subjects/areas is what I am after.

Help?

Avoid taking photographs of planes/aviation equipment in Greece. There was a well-publicised case a few years back where several british plane-spotters were arrested in Greece.

http://news.bbc.co.uk/1/hi/world/europe/1662165.stm (There's more if you look)

Could you post your nationality for the record? Some countries have tighter visa laws for certain nationalities - like the Chinese with US citizens, for example.

Since your first stop is Singapore - I would recommend getting visas for Cambodia and Vietnam there. I have gotten visas for both countries there, and it was relatively hassle-free. I had quite a bit of time on my hands, so I went with the standard processing, I think 2 business days for Cambodia and 5 business days for Vietnam. If you spend some $$, they'll speed up the process considerably.

Supposedly, Bangkok is also great for procuring visas, but I like the fact that Singapore allows you to get all of this done with people who speak decent English - not always a given in Thailand or elsewhere.

Assuming that you hold a US passport, here are my comments on visas:

Cambodia
Available on arrival, discard above advice
S. Korea
Not needed
China
Best to obtain in HK where it can be done in 24 hours at China Travel Services (many non-US can do the same day)
Vietnam
Needed, some missions can do same day, others, several. BAngkok or HK are probably the best/fastest places.
Thailand
None needed
Indonesia
Available on arrival
Australia
Elecronic Visa done automatically by airline
India
Needs to be done beforehand and best done from the US before you leave. Doing so in the US will get it done much faster and get you a five year visa rather than 3-6 months.
S. Africa
None needed
Tanzania
I believe available on arrival, but not 100% sure.
Kenya
Not sure
Dubai
None needed
Greece
None needed
Turkey
Available on arrival
Egypt
Available on arrival
Croatia
None needed
Morocco
None needed
Ethiopia
No Idea

And a bunch of EU/Shengen zones.
Not needed

To add to hfly's list above - Ethiopia offers visa-on-arrival at Bole International Airport in Addis as does Kenya at JKIA in Nairobi. Not sure about other ports of entry however.

Just one idea: if you're going to Croatia and have the time, do visit some other countries in the region as well as the distances are relatively short.

If you want to save money, inexpensive bus services cover most of the area. You could also look into e.g. Adria Airways' and Croatia Airlines' websites for cheap fares between the cities in the area. I think Belgrad, Ljubljana, Sarajevo and Ohrid (Macedonia) are all nice cities in that area. If you go to Macedonia, you can easily visit Kosovo and Albania as well - if you're interested in collecting passport stamps that is.

Somebody mentioned Hong Kong. Well, people don't usually visit Macau but I'd recommend it for short trip. You can get the Chinese visa in 24h there as well, and catch a bus to Guangzhou from the border.

This is true - however, it depends which border crossing you use. You will get a visa at any of them, it's just a matter of how much they'll make you pay for it. When using the land border crossing points from Thailand, Cambodian immigration will issue you the visa (official fee 20 USD) for 1000 Baht (25 USD). Guess who gets the extra $5? If you happen to share my aversion to stuffing the pockets of corrupt immigration officials, get your visa in advance. Or fly into Cambodia, at the airport you're charged the 20 USD you're supposed to be charged.

BTW, flying into Cambodia has become a lot cheaper since Air Asia (www.airasia.com) and Jetstar Asia (www.jetstarasia.com) are now operating routes there (from Kuala Lumpur and Bangkok on AirAsia, Jetstar from Singapore). Tiger Airways (www.tigerairways.com) can also be useful when travelling around Southeast Asia.

You won't be able to get all your visas in advance. I know China's visas are only good for 90 days and they seem unwilling to budge for US citizens even when there are other options officially listed. (There are longer-term multi-entry visas that we should have qualified for but my wife couldn't pry anything out of them despite spending over an hour talking to an official in Shanghai. We wanted to keep a current visa at all times because we didn't know when her mother was going to die.) I feel like Australia has the same limit but that was half a lifetime ago (and the rules might have changed even if my memory is right.)

I have been on two long many-country trips. We always got visas by applying for them in the country before the country we would need them in. The only time this was any sort of problem was with a visa for Indonesia obtained in Australia. The problem is we weren't sticking around in Sydney and they wanted something like an eternity to process it. We ended up having to have our passports mailed to Darwin for us to pick up from the post office.

hfly's advice is very good...

assuming you are American, you can verify this information yourself from www.traveldocs.com

for the Vietnam visa, I would get it in the States, unless you plan to spend a few days in Bangkok or Cambodia. In the latter, you can do next day service.

for Tanzania, I thought you had to get it in advance, but you can always check with the embassy

I've never gone overland to CAmbodia, only byplane. In any case while I understand the principle of not wanting to overpay for a visa, the prospect of not having to spend an extra day or two dealing/going to/fr an Embassy and dealing with the lines, bureaucracy etc. would be far outweighed by a possible $5 overpay at the border.

Actually the China limit on US citizens for the last two years has been 6 month visas, not 90 days, again its best to do in Hong Kong (or Macao) rather than anywhere else as the documentation required is less, and the turn around time much faster. Indonesia should ALWAYS be done on arrival, unless you need a longer duration as the VOA is valid for a month.

One thing may make your ventures a bit easier: Get a secondary passport. That way, you won't be screwed even if an embassy happens to have a slow day. I used to feel bad giving up my passport (even for just a few days) in a foreign country; you'll always be able to have one passport on you if you have two.

All ports of entry to Indonesia do not offer the VOA facility, or if they do so offer it only during select hours of the day. I remember arriving at Teluk Senimba by a ferry from Singapore around 7pm (with pre-arranged visa) and noting that the VOA counter had closed at 5pm.

I suspect the OP is entering Indonesia through either one of two (maybe three) ports, so VOA shouldn't be a problem. In any event, waiting to be processed at any VOA counter can be exasperating, especially after a long day of travel, so it isn't a bad idea in general to get visas in advance if possible.

On the other hand, plans often change, especially on a long trip, and you don't want to pay for more visas than you will actually use.

Having dealt with visa waits/lines at consulates/emabasies and on arrival in Indonesia, I can CATEGORICALLY STATE that the wait that one experiences on ariva; is infinitely less than one will experience at an embassy or consulate (You can wait four hours at a embassy/consulate on two seperate days, while the biggest wait I have ever seen on arrival is perhaps 20-30 minutes). 747, you are right, however I have the impression that the guy isn't taking a bus or Cessna from PNG to Irian Jaya.