Also there are a lot of rules for booleaning things in maya.

One thing I see that you are doing that is a no no is you are trying to bore a hole into the middle of an open face. Look at Dave's example.

There should always be an edge going from the outer edge a face to the object you are booleaning.

Search the site for boolean and you;ll find a list of all the rules and I think I even have a couple video's floating around that demonstrates a couple of the most common issues that bite new users on their bottoms.