Nashville's number system is an excellent way to start thinking about changes. At it's basic you get a simple blues progression looking like;

1 1 1 1
4 4 1 1
5 4 1 5

Now, I can't put in superscript here, so forget the sevenths, etc. for now. But you can see that same chart can be used for blues in any key. Start thinking in relational terms, rather than absolute ones (Bb, F#, etc.) and the job of transposing any tune becomes almost trivial.