There should be a sticky in the general section with a repair manual for your car. I had a haynes for my gen 3 and it helped me with everything I ever needed to do to the car.
I prefer to use toyota oil filters in my car, I think those would be your best bet and you can get good deals on them online if you buy them in cases of 6. TRD stands for toyota racing development, so that would be an upgraded filter, probably with better filtration, but it is hard to say. You should run 5w-30 or 10w-30 depending on the climate where you live.
As for online stores, there really isnt much camry specific since there arent many parts to have. Read all of the stickies in both the gen 3&4 forum as well as the general camry forum, use the search feature as much as possible, and enjoy your new ride
Damon