I believe that shooting for and submitting images to Microstock is a great way to pay for a hobby and develop your photography imagination and technical skills.

I love to help people get started submitting images for microstock, and love it even more if they use my referral links below!

Shutterstock:
http://submit.shutterstock.com/ (Link for Photographers )
http://submit.shutterstock.com/ (Link for Buyers )

Dreamstime:
http://www.dreamstime.com/

Istockphoto:  (Great site to get started with, now owned by Getty images I think)
http://www.istockphoto.com/

Fotolia:
http://us.fotolia.com/

BigStock:
http://www.bigstockphoto.com/