All the baggage questions are answered on their website:

http://www.ryanair.com/en/questions/baggage
http://www.ryanair.com/en/questions/table-of-fees

Read them carefully or you will pay the price when you get to the airport!

You must print your own boarding pass before you get to the airport and there is a cut off time to do this (maybe 4 hours before the flight). Be safe, logon and print it 2 weeks before you go and keep it with your passport.

A few things that AREN'T necessarily obvious for the first time flier with Ryanair:

If you are travelling on a non-European passport then you may have to get the boarding pass stamped at the Ryanair ticket desk before you go through security. This is NOT the same as the normal border controls where they stamp you in or out - it's something specific to Ryanair. They will tell you about this when you do the online check-in.

DON'T try and push the baggage or check-in limits. They will give you about 2kg leeway on checked bags (probably less on handluggage) and then they charge you a lot of money.

They do spot checks on your carry-on luggage at the gate so don't think you can flout the rules and get away with it. If your handbaggage is overweight then you have to pay to check it in at the gate.

If you buy duty free then you have to put it inside your hand baggage. Strictly ONE bag per passenger including things you brought at the airport and it will include a ladies handbag if that's too big too.

Note the check-in and boarding times and DON'T be even 1 minute late or they WILL deny you boarding with no refund and you have to buy a new ticket. Sit on the plane conforted by the thought that you aren't going to be waiting for "the last remaining passengers" who board late and delay the plane by a couple of minutes so it misses it's takeoff slot and is then 20 minute late.

Flights are generally 90% full so if you want a window/aisle seat then pay a few Euros/Pounds the priority boarding and get to the gate before they start boarding and you will get the seat you want. Waltz up to the gate after priority boarding is complete and you will have to take whatever seat is available.

Get something to eat in the airport