Collecting paperbacks

I started collecting paperbacks (mostly books I read when young). Can anyone indicate some good online resources? (Grading, collectability,...)

What kind of paperbacks? There are all kinds of resources out there. One of my favorites for paperbacks is http://www.bookscans.com/. This is actually a website Tim should be alerted to and perhaps work out an agreement for some great covers.

Thanks, I had a look at the bookscans site; really interesting. Anothet site is Gryphon books, and Vintagepbks.

I'm collecting first paperback editions of authors like Ellery Queen ,Ngaio Marsh, Edgar Wallace,... Editions from the sixties. So the first printing of their works in paperback.

All suggestions would be welcome.

Merry Christmas to all of you.

if one is a serious collector of paperbacks it may be wise to spend some time to learn the deacidification process. My bookbinder charges me $35 per book and i suspect i am going to take my own advicae this year. i also like 1st paperback editions, therefore entering two copies of, say, the wayward bus by john steinbeck, the 1st paper and the 1st hardback.

Reviving this old thread by answering the original post question...
For book sources I recommend "Cumulative Paperback Index 1939-1959" by R. Reginald and M. R. Burgess and "The Paperbound Book in America" by Frank L. Schick.
There is also "Paperback Prices and Checklist" by Graham Holroyd, printed in 2003, so prices are out of date, but it has good information about Paperback Originals (PBO), 1st Printings, Artists, dates, etc.