Look for a book called Photoshop Tips and Tricks. I can't recall the authors name offhand but he is the editor of a monthly PS magazine. Great book and it gives you the exact procedures to alter photos. Way better than the PS manual.
I have that book and 2 others. It is good, I can attest to that. There aren't as good for me as a regular Photoshop user because designing stuff for t-shirts is totally different than doing picture altering or regular stuff. I still do some of the tutorials just so I can be fluent with non shirt related stuff though.
That is a good book and I will look to see the others I have. They are good as well. I would buy too awful many books though because most of them have the same info in them worded differently. You can usually get them at most of your big book stores, ie: Borders, Hawley Cooke, etc. I would recommend going there and looking through the books and find something you would like to try and get that one.
If yuo need any help with something, get a hold of me and I will try to help. I am swamped right now, but could spare a little time to help a brotha out.