The hardware itself, like RAM and the actual board would be harder to make, so I will buy them.
You have to ask yourself what you're planning to get out of this. If you want to be like Jobs/Woz and create a new design then that's certainly possible. If you want to build an existing design, then you'd certainly learn a lot of soldering skills - but you'll learn more of the 'how' than the 'why'.
From that point on, I would like to create everything myself and write the software. I didn't thing it would be that hard (Woz was 21 and had almost no college education when he created the Apple I).
The best electronic and software designers are self educated! Woz didn't create the Apple I because he was uneducated and it was easy, Woz created it because he was a self-made electronics genius who had spent tens of thousands of hours all through his teens reading data sheets and building other designs. He had the drive to learn this stuff.
If you're really good at electronics, a lot of this stuff becomes subconscious - you can just see circuits working by glancing at a diagram. Woz would have been on this level and above... these days no-one would design a 45-IC game in their head, without using some pretty sophisticated design and emulation software. Woz could do this in his head.
Most people can never 'see' electronics in this subconscious way, and formal education makes little difference to that skill.
I am 21 and I have experimented with electronics very little (soldering stuff in my grandfather's garage etc.). I am very eager to learn, but there doesn't seem to be one coherent place where I could find all the information, categorized and easy-to-understand. Maybe Khan Academy?
I'm sorry if this sounds negative, but I don't think you're going to do this. If you haven't had the interest and drive to suck-down this knowledge in your teens, then I'm doubtful that you'll have the motivation to really master it now. The information is all out there - there have never been so many books, online resources, online data sheet libraries etc. You have hundreds of times more information at your fingertips than Woz had - you just have to hit google.
Here's a
datasheet for a 6502 varient as a start. Woz wouldn't have had much more to go on when building the Apple I - but this would have been enough for him.
Seriously, look into Arduino - it'll give you an easy entry point - with a great deal of great documentation available in books, on the web and even
example podcast videos. You'll need to learn a LOT to get going with Arduino - and that'll be 10% of what you need to know to design, build and program a custom 6502 board. It's an ideal first step.
One of the best things about Arduino is that the microprocessor has it's own memory (RAM and flash), so that cuts down on circuit complexity a LOT of you want to design your own board. You can take the processor chip off an Arduino board and get it working on your own board with only a handful of extra components.
