The best advice I can give is to be bold; ctrl+Z will be your close friend as you explore tools. I did a lot of 'hmmm; what will this do?' and then either 'cool!' or 'ugh; undo!'. Also, layers are great; when you want to try an idea but are unsure how it will turn out, duplicate the layer by dragging it down onto the new layer button on your layers palette, and then hide the original and do what you want to the duplicate. if it turns out like garbage, just delete that layer, make the original layer visible, and go from there.
It will help if you have had some experience with graphics software, but not essential. Save files of examples of effects or combinations of effects that you like. If you are working on something and your experimental blur or whatever is not right for that piece, but is cool, then copy/paste it into a file and save it as 'blur A' or whatever. Also may want to write (in that file) some quick notes on how you got to that point.
Experiment, experiment, EXPERIMENT!!
Good luck!
-E
(NOTE: Self-taught AI user; I may not know the best way to do something, but get good results)
'There is no LEASH LAW for the IMAGINATION!'
myspace.com/erixworx