Rather than attempting to reinvent the wheel and explain this complicated process myself, it is easier to post a link to this excellent article on the structural training of young shade trees. And it is nicely illustrated to boot!!

I would suggest you read this carefully, paying close attention to the training processes involved with the decurrent (leader-less) types, as this includes all maples. Your focus while the tree is young is to encourage the development of scaffolding branches or the main limbs that emerge at a proper distance along the trunk. No, you do NOT want to cut off the top and the link will explain how you approach these congested angles.

Come back if you have further questions. And you might look into acquiring a pole pruner or saw to help you reach those upper branches.

gardengal48, thanks for the excellent resource link...I looked over the article and it covers the basics well. I'm still a little unsure what to do in my particular situation, where an entire whorl of branches is at too-tight angles. I've circled the area I'm concerned about. Do you think that group of branches is all going to have to come off, or given that they're still fairly thin (around an inch, maybe less), could they be weighted or tied to the ground or something? I suppose if they're roped to stakes from that height, the wind could be pretty brutal on them, eh? Thanks again.

Can't see clearly how many branches are involved, but the removal of one or two now might be advised. Try to leave ones that are not necessarily emerging at the exact same point around the main stem if at all possible.

No tying or staking or weighting :-))

Four, right at the same height on the tree, all at very tight angles. The best i can figure to do is to maybe take out all but the "least-worst" one, but I'm afraid it's going to create a pretty big gap. On the other hand, the tree might also put out some new attempts right around there, and then I can pick and choose which of them to keep.