I don't think these 'quick intro to bitwise operations' and/or 'cool bitwise operation tricks' articles ever go into enough detail to be safe.

Bitwise operations can be _extremely_ useful, but it's surprisingly difficult to use them in a correct and portable way. I have no idea where you can go to learn all the intricacies involved.

One killer that's always listed is "divide an int by 2: n >> 1" with no reference to how it behaves differently than the "/" operator (bitwise rounds towards negative infinity, / rounds towards zero). It's not incorrect, but that detail can be extremely important.