Writers Dock is quite a good one, with lots of groups and forums to get the creative juices flowing.
A good habit to get into is that of keeping a notebook and writing something every day. If you're not sure what to write at first, time yourself. Open the notebook, take your pen or pencil, and write. Keep going for two minutes and no longer. Doesn't matter if what if what you write is just a load of gibberish - you're the only one who'll ever see it. Very soon you'll find more and more ideas going into and coming out of what you write, and you'll find yourself wanting to write for longer and longer. and then there'll be no stopping you.
Also, read, read, and then read some more. If you want to write, then you really can't read enough. Anything you like. It's all inspiration. You can afford to be a bit more picky once you've established a writing habit and are beginning to specialise a little more.
Have fun!