Even without registering to be a member (which I haven't done... yet), this site has a wealth of useful explanations, often given with interesting perspectives. I'm particularly fond of the article that emphasizes just how huge the range of organic pKas is and the series of articles that teach the different types of stereoisomers using cats. There is more material available for first semester topics than for second semester topics.
This is an iPad app (only for iPad, I'm afraid!) sponsored by the Chemical Heritage Foundation.
What it does is to simulate an old-time chemistry set, with all the dangerous chemicals. You start with alkali metals in water, and work your way up to heating reactive metals in air with a blowtorch, and mixing alkalic metals with halogens. There's a strong emphasis on BOOM.
Unfortunately this is not suitable for classroom use, at least for me, because you can't get random access to particular reactions. But it is a lot of fun to play with, and perfectly suitable (recommended) for children.
The YouTube promotional video is below.