In the dojo where I train, Sensei tells you when you're going to test and tells you to get ready. We log time as well though he usually knows who's there and who's not so I doubt it makes a big deal.
The best piece of advice I'd give is to Relax. It'll help in every aspect of Aikido I think. Taking Ukemi (not sure of the spelling), finding your center, preforming techniques, testing, everything. Just relax and things will happen in their own time. Don't worry too much about testing.
The first few weeks I started I told myself I was going to reach Shodan within three years. But I soon realized through my Sensei's example that rank really doesn't matter, it's the skills associated with that rank that I want to attain. Sure I will continue to test and to strive to reach my goal, but if I fall short, it doesn't matter. I enjoy what I am doing and my skills improve a little more every day.
Eventually the nervousness and shyness will pass, after you've tossed around people twice your size your confidence starts to grow
In any event have fun with it and don't worry too much about testing, when the time comes, AikiWeb's still here with it's wonderful collection of people and advice.