You'll be surprised: there's nothing special to expect!
If you booked at a low rate you will get what you paid for: transport.

Just make certain you have printed all your boarding pass in advance, your passport details match your reservation (in case of mis-spelling they'll send you to the ticket counter for an expensive correction and then time gets short) and your checked-luggage is within the unusual low weight limits (they get particularily fussy about this in the holiday season when they seem to make more money on overweight then on tickets) and the exact quantity you reserved for (otherwise it's off to the ticket counter again....). And be at the airport in time since Ryanair means standing in line at few check-ins and few security checks they pay the airport for).
In spite of the noise they make in advance Ryanair are not very strict with carry-on measurements, because the staff knows many passengers are on connecting flights and due to Ryanair policies are forced to take as much carry-on as possible - so expect full racks.

After standing in several lines expect to rush to the aircraft because every party wants connecting seats in spite of no seat reservations (by this they make additional money for priority boarding).

Ryanair's maintenance is said to be very good (that obviously does not include cabin cleaning by the cabin crew in the 20mins between flights), but their attempt to be Europe's most punctual airline (not much of a task when you fly from one remote cowshed to another without having to wait for connecting passengers) is known to put additional pressure on the cockpit crews.

"the assault of goods and services being thrown at me". You'll get much more of this. Ryanair flights are like promotion excursions. You can't get any sleep, but your flight is short. "Drinks, drinks anyone?", "telephone cards, telephone cards anyone?", "snacks, snacks anyone?" (prices of which are fair), "inflight-shopping, inflight-shopping anyone?", "bingo, bingo anyone?", "garbage, garbage anyone?" (they pull a plastic sack through the plane to collect the leftovers and since you'll find no seatpockets to stuff anything into...).
In case you are one of the few lucky passengers to be handed the really good inflight magazine: sit on it, they will try to collect them again prior to arrival.

All this is a bit of an exhausting pleasure and takes any glamour out of air travel. That's totally acceptable if you are lucky to get a low rate, but less admirable if you're heading for a long business meeting, got a connecting flight, have to take a long drive to what Ryanair calls airports (Ryanair's VIENNA is not even in Austria and I've seen quite a few oversea's tourists in Hahn in search of their onward flight from FRANKFURT) or in travel season pay a rate comparable to REAL airlines.