... Did you visit many main story line quest dungeons before you were "supposed to", and did it break any quests?...
... I assume you just amassed shouts and had to sit on them until there were dragon souls to unlock them?
I tried to avoid most of the main plot points - and just did a lot of "kill this bandit, punk that giant, fetch my grandpappys lost sword" type quests.
I did clean out some stuff in a few main halls where I knew there was a lot of things I needed for leveling - metal ingots for example - some MAIN quest places have nice treasure deposits, It didn't seem to effect anything too much though - seems by the time I did the quests for real everything just re spawned.
So no real issues with pre discovering quest places - just leave NPC's you accidentally find well alone (Unless you WANT to actually start whatever quest they belong to - which I'm SURE you will actually get directed to eventually when its time anyway), and everything went just fine.
I had done a LOT of just running around sounding out locations on the map and that was AWSM to finally play the game and know where almost everything was already - or at least have a location very close already marked.
And yes - piled up a LOT of disabled shouts as there where no dragons yet, but to be honest 99% of the shouts are completely useless anyway, and even though I have souls now I just don't bother with them - I really only use "Slow Time" to deal with those SUPER ICE MAGE guys who shoot icicles like a goddamn mini-gun - just go all bullet time run around behind them and off with their heads...