It amazes me that people would put coworkers second. Those people can be very annoying because I feel like their only purpose is to leech knowledge rather than do any real work. OP's list is the lazy programmer's list. Taking breaks to think about the problem is good, my order of operations is something like:

   1. Google
   2. RTFM
   3. Think
   4. StackOverflow
   5. Coworkers/IRC

Even going to IRC can be dangerous, was told to read the f-ing kernel source when trying to ask questions about the darwin kernel API documentation once.

I like that order. Don't waste your time or anyone else's if it's a simple problem that can be solved with a direct Google search. But definitely think before asking.

I go to coworkers when I think it's a problem they've dealt with before. Otherwise, it's much easier to just Google it.

I would put 'Think' first on my list though because I really enjoy it, and tend to do it whenever I can. Google comes in when I hit a dead end thinking.