I've been wanting to do this for awhile but couldn't find a crossword site that a) let you make both newspaper and classroom style puzzles, b) let you post it online so that it could be solved online, and c) was FREE. This site does everything but let you make the more difficult newspaper style puzzle (d'oh).
The buttons at the bottom of the page allow you to either print the puzzle or solve it online. The online version is a bit wonky but it works. Message me with any bugs. Enjoy!