Some rooms are still open to US players, but not the likes of partypoker... hunt around and yee shall find!!! https://secure.partyaccount.com/faq/us_legislation.htm
I found most books to be absolute shit. There's a classic book from the 60s,70s (not super systems) written by a famous house player(back when they didn't have internet yet, sonnie). The book can be found freely on the web, Let me try to remember the guy's name and I might give you a link. It opened up my mind, and he's not cheap, he gives a play by play of EVERYTHING, it's just that he uses 5 cards( another old relic you kiddies might not remember) so the action is a bit different. I once found a book so bad, it was a collage of other books, just random chapters, not making any sense even, and the guy started "In my 10 years of playing poker". edit: the link was on the first page of Google, lol. The guy IS famous. Poker: a guaranteed income for life. by Frank R. Wallace http://www.neo-tech.com/poker/
Agree on the Sklansky and the Harrington comments. The Harrington books are so thorough they are overwhelming just from the sheer amount of information, but also so well written that they aren't hard to read. Just finished the third one 2 days ago. If you liked the first two, the third one is great too. It is all sample hands, but some of them he goes into more detailed analysis of what the players were thinking when they were played out and what you should be thinking too. I would recommend it.
you can still play on full tilt i believe..but you cant fund it via net-teller...you must use other options available at full tilt poker website like epassport i believe is one...but be very careful how much money you transfer..I still cant get my money out of net teller...so eventually i see the rest of the cash transfer options being closed soon...
I would definitely recommend starting with volume 1. He lays down the foundation in volume 1 and 2 and shows you the basics of how to use them. Volume 3 pulls everything together and goes into more detail on various aspects.
The harrington book is more for tournaments. Read the sklansky books for a basic understanding of poker theory. Then just start playing and practice, which is the only way to get better. Learn how to adjust to your opponents. That's basically it.
I found some pretty good free advices from here http://www.straightmansweb.com/ in fact also got lot of free poker money from there too to start up with