I'm planning to go as well.
Like dcro I would say go for a maximum of 2 events per day and seriously consider if it's smart to go for 2 if one is some distance from the central parts, especially if you're going for handball (which is in Lille)
And don't expect to get all the tickets you hope. I got little less than half the tickets I tried getting for the 2012 Games. Managed to add some later but ended up with jus 1½ week in London and not the full duration.
And certainly. Be quick getting a room when it's possible about a year before.
I wouldn't be that worried about transportation a long time before other than making sure you can make it from one venue to another if you go for more than one event a day.
And last, consider going for something you wouldn't think you would watch. I had a blast when I spontaneously got tickets for MTB and women's freestyle wrestling in London!