We have a peach (halehaven, I believe) in our small suburban backyard and it has been sorely neglected. This is its 6th summer in the ground and it has never given us fruit so we just assumed it needed another peach in the area and would never set fruit so have pretty much treated it like a shade/privacy screen tree, only pruning it minimally after the first winter. Well, lo and behold this year we have a tree loaded with fruit! (assuming now that the the previous lack was due to late frosts?) Anyway, I've been trying to read up on how to care for it so it will continue to set fruit in the future but unfortunately didn't get to doing anything soon enough and one rather large branch is now cracking and touching the ground already with months to go before they're ripe. I need a quick reference guide for a complete and total fruit tree novice so I can try to get this tree back into good health. I know I need to thin out the fruit but am not sure how much and also not sure what to do about the cracked branch.

If a photo would help I am happy to provide one, but if there is a general reference that is good for beginners I'd appreciate a link. I'd hate to have more branches crack and end up losing the tree to disease.