the best way to learn stuff is:
read tutorials and truly understand them!
then try to figure out stuff by your own and practice, practice, practice.
also, find a GOOD mapping community where you find questions about almost everything that you can think of (i.e.
www.thewall.de <- haha to all poop ppl who are not able to read german
<- best mapping site ever)
so, whenever you're stuck on something, visit a mapping comminuty of your choice and search their forums. then, read DIFFERENT solutions for your problem and vice versa, etc etc ...
and now all that stuff i just wrote in short: learning by doing.
beeing a smart and creative mind is a must aswell ... just btw.
hope it helps