I can't be the only person here who has fond memories of the problems in Vinogradov's Elements of Number Theory. (For people who have not read it - the text itself is just a concise basic number theory book; most of the substance is in the problems.) At the same time, much of what is good about them became clear to me only later. Vinogradov does not give citations or credits (not even to himself!), let alone any sort of historical overview for why the ideas he introduces in the problem sets are important. Standard names for the theorems the student is asked to prove are also completely missing.
Wouldn't it be a good idea to craft a commentary on Vinogradov's problems? Has anything of the sort been already done?
(Incidentally, something learned there recently made its way to http://polymathprojects.files.wordpress.com/2010/07/polymath1.pdf)