If you can already program then I'd say that site is no better no worse than many others out there. It's just a case of sitting down and working through a structured book and posting on forums for things that don't make sense.
If you're new to programming then I wouldn't start with vb.net - no doubt others on here will disagree with me - but to fully understand the whys and wherefores of .net I think you need experience of a small, "older" language to see why .net has developed the way it has.
IMHO I'd start with understanding variables, if statements, loops, functions, passing and rec. paraments/arguments. Then when you've got all those under your belt and you've written a few small programs you can take a look at .net.