The best thing you could do, is go to 1 SW class, pay for membership, get the books and then if you decide you still want to do it alone then go for it. That way you're equipped with everything you need to follow the plan successfully. It will be the best £15 you ever spend and will save you A LOT of time trawling the internet looking for syn values.
SW have their own app but in my experience it's not very good...at all. I would definitely prefer the books and for anything that isn't listed then google.
Good luck.