Not exactly a place to ask questions, but this (to me at least) serves as a pretty good Q&A resource: http://www.tricki.org/ http://www.tricki.org/ "a Wiki-styl

Not exactly a place to ask questions, but this (to me at least) serves as a pretty good Q&A resource: http://www.tricki.org/ http://www.tricki.org/ "a Wiki-style site that is intended to develop into a large store of useful mathematical problem-solving techniques"