All about file formats, sharpening, colour profiling, resolution... boring stuff like that. Still, worth looking at if you're a geek, have technical specs or are a designer.
I've brought together all those common questions about things such as usage, copyright, licencing and your own rights concerning the intellectual property into a separate FAQ. I follow standing industry practice in this area, where you are paying not simply for the labour costs of producing the images, but for the right to use them. I recommending reading through it if you have any concerns.
Follow this link for a copy of all my terms and conditions exactly as they are written out on the reverse of all my documentation.