It's actually a good idea, I think a lot of people could benefit. The Ponoko frontpanels can easily compete with aluminum ones, especially as they are usually not so large and stability/bending is not a big problem. However, it's not necessary to create a tutorial, there is a lot of information around already:
1. If you just go to the Ponoko website you can find a number of good hints.
2. Over at the Mutable Instruments forum you will find a very nice and useful tutorial from schrab(ikus).
3. For the notches of the case, go over to rahulbotics and enter the dimensions of the case. The notches will be created automatically and you get a PDF which you can then use as a basis for your design.
Just do it - start with something easy before you go for an expensive panel.