Well, you can always ask your friends for advice... ;)

The most important thing to look for in a book you're considering buying is whether or not (1) it has pictures of what you're doing with your hands, and (2) whether or not those pictures make sense. :) I find the ones in Stitch'n'Bitch to be pretty good (tho' I did pick it up long after I started knitting.)

As far as knitting in the round goes, get a 16" one for a hat, in whatever size you decide you'll need. Knitting a swatch is *always* a good idea (although for small projects like hats I admit I don't bother very often any more, unless the yarn is totally new to me.) Once you start knitting in the round you won't want to stop, though! No seams! :)

The most important thing for knitting in the round is making sure that your stitches aren't twisted after you cast on, and before you connect edges. (Ack! I need to be able to draw this!) So you cast on just like you normally would. Then look at your cast-on stitches. Make sure that the bottom edge of the stitches all face the same way (down). Now the free end of the yarn should be coming from the needle end that's in your right hand, and the first stitch that you cast on (a long time ago) should be on the needle that's in your left hand. Double check that the stitches all point the same way. Now you'll knit into that stitch that's on the left-hand needle just like you'd knit anything -- this will close the gap and make it a continuous circle. After that, it's just following whatever pattern you have.

Hope this helps, hon!

-Arwyn