I was hoping someone else would know of one.  I personally don't know of any contests that are really geared towards the novice.  I'd say if you lack inspiration that's a  big problem : p.  I find my from anywhere - a thought, a movie, a passion.  My images rarely turn out anything like what originally inspired them (ok with my Lilith work sometimes they do).  Just look around, you will find something if you are looking for it.  Take a look through the galleries.

Good luck to you!

I am:  aka Velocity3d