try bryce. it lets you create 3d shapes easily.... pretty good program to start with...

i made the 3d objects in these pics with bryce.... just the 3d objects though, the rest was photoshop

http://www.deviantart.com/view/141758/
http://www.deviantart.com/view/143692/
http://www.deviantart.com/view/142242/
http://www.deviantart.com/view/181534/

and these i used 3d studiomax + photoshop

http://www.deviantart.com/view/183515/
http://www.deviantart.com/view/150296/
http://www.deviantart.com/view/149474/

though these might be kinda out of trend right now... these were made 2 years ago

parturition and iron shards are probably my favs tho