I've built 4 planes from plans and built about 25 kits. There will be some contention about this, but usually a kit is cheaper. Case in point: I spent about $160 for everything to build a Cloud Dancer 60 from RCM plans (this is with all of the parts and hardware). This was before Ace Kitted, then ARF'd it. The kit was way cheaper and then you don't have to do all the work. If you are looking to save money, as it looks like from the bottom of your post, then you should buy a kit. The ONLY case where I have ever heard of people saving money by building from plans is when a club gets together and buys a large amount of wood and makes many "kits"for one design.

If you decide to spend the money and go for it, then an exacto knife will do fine for a small plane or a glider, but for anything 40 sized or bigger you will want to have a band saw and a belt sander. Put your plan on your wood with 3M double stick tape. They even make a kind that comes off good. Then cut around the lines leaving about 1/16th of an inch. Then belt sand right to the lines. Make yourself a "kit" then just build it like any other. I'm sure a search on "plans building" here on RCU will give lots of info.