To elaborate on design patterns (being somewhat related to lifehacks): Christopher Alexander et al. (Thanks @susanc) write about design patterns, starting with architecture (sconces for hiding unsightly window stuff) to software (creating a singleton object).
How to find these online depends a lot on what sort of problem/solution you are looking for. If it’s software, there are lots of sites that show up in a search ‘design patterns in <insert your favorite language>’. Most of the problems are similar (provider patterns, singleton patterns, etc…), The solutions will often depend on the language and even the philosophy of the software platform. [e.g. Linux folks will solve things differently from Windows folks, or Mac folks]. I’m a windows guy myself, but Sun/Java have a really good site on design patterns.
As for life patterns, this is sort of a new concept for me, but I think you might need to decide a narrower category of the pattern before searching. Is this a housekeeping problem? (Like sorting socks) or a school problem, (like the best way to keep notes). Or a work problem (like how to run a meeting). And then search for solutions.