Sounds like a great idea! As for resources, there are a few I'll mention. I read some good books, the most helpful was Fly Rod Building Made Easy
by Art Scheck. There are a lot on Amazon, but I got good ones through the public library, loaned from across the State. There are some YouTube videos, just search for 'rod building' 'starting rod wraps' , etc. and you'll find resources. In addition, this forum has some great folks that can help, as does Rod Building (Powered by Invision Power Board)
. The search engines on both will answer many questions and the members will be invaluable.
Regarding finding the spline, Sevier Manufacturing's blanks come with faint lines marking the spline, so that could make it easy. I'm currently building on my second Sevier blank and love my 7'6" 3/4wt (In my experience it doesn't work well as a 3wt but is a great 4wt). Having the spline marked could give you a chance trying to 'find' it and then check how you've done against the marks they made. I've never used a kit. I like making my own grip and find it not that tough to do, and I like picking out the components I want and it's easy to do. Someone else might be able to recommend a good kit. If you can, get guides with pre-ground feet. It's not the biggest deal to do it yourself, but on your first build it might be good to have them pre-ground. I would get a drying motor. It will make life much easier and give you a nice finish. Companies that sell rod building stuff will carry motors or search ebay. Other people take apart an old microwave or rotisserie, but I found ebay much easier.
Rod building is very addictive and there is always a lot to learn - that's the fun of it. I'm currently working on my first feather inlay. You'll do well if you don't stress about not getting everything right the first time (or the fifth). Until you put finish on the wraps, it's no big deal, just cut the wraps and re-do them. It's worth it to do it right and the rod you built with some imperfections will be more enjoyable to fish than a perfect, factory bought one.