I find photoshoptutorials.com a good spot when you're looking for guides on particular functions. Otherwise utilize Google, there are a million tutorials out there just waiting to be read
If you want draw something, try to search: CS4 for beginners or similar things
If you want to code your .psd to convert it to web template, so you need to find something similar to: turtorial code .psd to your cms or html (xhtml).
Good Luck and do not forget to show your works for us
Have you ever tried youtube? There are lots of photoshop tutorials on there. Also, photoshoptutorials.com, like Zendevi mentioned, is a good place to go.
I personally though, I love reading book based tutorials.
You can create a visual representation of a web page template layout in Photoshop but to make it functional on the web you then need to recreate it in CSS.To use Photoshop to create a sample layout for later conversion to CSS I would look at many different existing page layouts for inspiration and ideas. Pay special attention to the various page widths (in pixels) so when you begin work in Photoshop you can start creating your new document at a good standard width.