I personally don't anymore, however you will still people argue to prefix for scope.
I go with Microsoft and use their Capitalization Styles for all naming conventions. The entire "Design Guidelines for Class Library Developers" section, which that link is a part of, is pure gold, in my opinion.
Additionally, I love the "Framework Design Guidelines" book from Addison Wesley. It covers all of these guidelines with annotations from Microsoft team members on to why they recommend what they are proposing and how it is adopted within the organization.
