Don't use the gaussmarkov Eagle libraries... they're super outdated and not very well designed by today's standards. They were a game-changer when they first came out, the first pedal-friendly set of libraries for Eagle, but they don't hold up well in 2020.
His tutorials aren't great either - for example, restringing is the absolute wrong solution to any problem.
I got started on these libraries back in the day and since that time I've updated nearly every aspect of them - pad sizes, outlines, and pin numbers (for some reason many of his transistor packages are numbered in reverse to convention and this caused me to wreck a few boards early on). And I had to intentionally forget most of what I learned in his tutorials.
For tutorials, there are a lot on YouTube that have been made by people in our community. Here's a good series by Effects Layouts from last month, so it's hot out of the oven -
That's going to get you a lot farther than some 15-year-old resources, as influential as they were at the time.
