I can assue you that there will be.. 10000 guides will pop up with in a week after the retail launce.
Just think back on the community on D2, it was MASSIVE.
And D3 have got even more attention and the internet has evolved even more since this time, ergo you will see ALOT of guides on all classes, specs, methods =)
Im thinking of making some guides myself. I remember my countless lvl 90+ deaths in D2 and I dont want ppl to feel that, i does take something out of you when it happens. Yes its a game, but you still die alittle bit inside when it happens
There will be huge amount of guides, its just a matter of time, You will need a sharp mind to filter valuable ones from not so great ones.
Just now, You can start off with a plan for You and Your friends which You are going to play with. Pick up roles/classes in party for eachother, set up rules and frequency of Your gameplay (as far as its possible).
Be aware of mf/gimping stats issue. If You are playing with friends, that should be no problem, You can easyly set up a border of mf that You shouldnt pass, in order not to gimp Your stats too much, set it to be equal for all of You and it should be fine as none of You should be leeching then.
Playing in public games can be an issue with leechers sometimes tho, I wonder what kind of solutions ppl will advise to deal with those...
As for chars also, You will need to find a proper ballance between def and dmg output. 2 skills and 1 passive for def seems fine to start with. You can allways adjust starting from this.