The toughest part I have learned about building for someone like me (and sounds like you) is thinking ahead to your measurements. A friend helped me so that is where someone with some experience can really help. Just little things like remembering the thickness of your T1-11 or siding and taking that into account when you lay out your floor so the edges overlap etc. There are some very good step by step "shed building" videos on you tube that can really help.