Gruss forum  I visit here regularly, for obvious reasons. A lot of help can be found, especially if you use the search facility.

Green All Over An active blog and good read, varied content but mainly on topic. Blog roll provides a good hub for worthwhile browsing.

Machine betting Of interest to me being automation based.

Betfair Pro Trader No longer added to but has interesting posts. The author has two books published for automated trading.

Most of my questions are answered by doing a Google search but I favour certain sites for repeatedly having good, useful content. Here are some –

MrExcel and MrExcel forum I’ve used many tips and snipets from here.

Excel Easy Useful examples.

MSDN Although I’ve not used many examples from here, it is good for understanding syntax and parameters of methods.

Stack Overflow Sometimes very useful. Sometimes absolutely mind-numbing, with answerers going off on one because the question wasn’t set out correctly, or some other irrelevant point.