Welcome to the ipod touch club. I have an older generationi ipod touch 2g but thats all i can afford really.
If you have a lot of PDF books you can check out GoodReader. It reads large PDF files well and it cost only USD0.99
I have
a review here on GoodReader at my Weblog and at the bottom you will see how its layed out.
Alternatively There is GoodReader Lite which is FREE the only limitation is that you can only keep 5 books or file on the device at one time