Gary, if you are concerned about setup and aren't really sure, I would suggest starting your tuning after the string is shot in and retune the arrows from scratch (with silencers and the nock point you plan to use attached on the string). A search on here for arrow tuning will give you 1000 posts to read, or visit OL Adcock's website to learn more.
Holler if you need more detail, I'm sure we can all contribute to getting your arrows flying the way you want.
Shawn's right, usually a string won't break unless it's been abused (nicked, cut etc.) or there is something on the bow's nocks causing an abrasion. Discard a string if it gets nicked or if it becomes so frayed it looks "fuzzy". Periodic string waxing will prolong the life quite a bit.