Tell me about Birdhouses

This year I put up some bird houses for the first time, and built an owl house with a friend that has yet to be put up.

Information about bird habitat is both sparse and overwhelming somehow. I'm wondering what everyone here has done, what has worked, and what you've learned to do differently. My understanding is that there are many different types of houses with different entrances and considerations. Obviously it varies place to place, but I imagine there are many similarities.

So, please tell me your thoughts and practices!

You are correct, different birds have different needs.
In Australia there are lots of web sites detailing what is needed.
I image such details will be available on bird sites. I will have a look.

I put up a great little hanging wren house,  I love those little songbirds.   They didn't find it the 1st  year, but they did the 2nd year and raised 2 clutches.   They are great fly and mosquito control and their song is lovely too, for such a tiny brown bird.  This was year 3 and not that I hate chickadees, but they were in the house when the wrens came back  :(   After a day or two, the chickadees decided it wasn't the right place for them and they left, but the wrens didn't come back.   I'm going to get a 2nd one for next year.  

Here are some basic details
/National-Wildlife/2010/Best-Bird-Houses

And it has other links.
good luck with them.