There are many ways to do this, and there are threads here about it, if you'll only look through the thread titles a bit.
Google is also your best pal when you want to know how to do something. Use the following format to enter your search termsphotoshop tutorial|technique *terms for technique go here*The ---> | <--- character acts as a Boolean "or" operator in Google searching.
Here's a compendium of links to get you started.
<http://www.adobeforums.com/cgi-bin/webx?128@@.3bb80e5d>
Click the link.
Bookmark it.
Start reading and follow through to tutorials.
Work the tutorials.
???
Profit!
:)