I plan to do some side quest, join a guild or two, and establish my self in the area alittle, maybe get a house, get married, that kind of thing. Once I'm level 15-20ish I'll strt the main quest, but still do side quests as they come up naturally.

I plan on starting the MQ in a year from now approximately.

I was first planning to do the honorable Voldur character first (a completionist walkthough), but I decided to start with a sociopathic khajiit named Rhuja, who's going to wreak absolute havoc (testing the game boundaries). He'll most likely side with neither the imperials nor the stormcloaks, possibly breaking the game unless it's possible to beat it with a third, neutral option (if the war is even necessary for the game to be beaten).

Once I've broken the game or beaten it with Rhuja, I'm gonna start with my Voldur character. He's anti-imperial, believes in a "free people" and his actions are hard but fair. The Main Quest will be followed until the later missions. I'll postpone those until I've completed most quests.

In both Oblivion and Fallout 3, I've typically had a pretty even pace of MQs. I usually do 1-2 MQs, then take a break and get a few more levels, then another 1-2 MQs. I typically wait with the final MQs till I'm maximum level. For Skyrim this would obviously be around 45-55 levels, although I may wait till I'm in the 70s, when all skills are maxed out.