My 2 cents.
I learned how to build rifles from my wife's late grandfather who at the time was a well known BR smith and shooter. He was in his early 80's when I met him and I started taking an interest in rifles. He was kind enough to let me for a small fee chamber and build my own rifle under his guidance. He was still busy at the time, but I went out on weekends and the odd late night. He basically lived in his shop. My first rifle was a hart barreled 308 Norma. Shot 1/2 MOA or better on regular basis. As time went on I was able to build 4 more rifles in his shop. As I became part of the family my shop time cost went down to helping him with day to day chores. Was never free.
During this time I was obsessed with reading everything I could on rifle building, shooting, ballistics, bedding techniques, chambering techniques, cartridge design, trigger tuning, timing, truing, and stock work. Basically anything to do with a rifle. Some of the old books such as Gunsmithing by Roy Dunlap still contain some very good information that is hard to find online.
Current production DVD's such as the ones named above give you a really good idea as to what needs to be done but as mentioned before the "feel" of doing things such as chambering is only learned by doing it. I've seen some horrible videos on youtube showing a "Professional Gunsmith" reaming a barrel and the thing is screeching and chattering so bad, but he keeps going through the whole chamber job. Would hate to see what that one looks like.
I learned to work a lathe backwards. I first threaded and chambered then learned how to run a lathe doing general lathe work after the fact. After he passed away I was lucky enough to get a job at another shop for $9-10/hr something like that doing basically muzzle brakes, and the odd chamber job along with a bunch of general repair work. I was able to get that because at the time I showed him a rifle I had built which was just as nice as the stuff they were putting out. A few years of working construction during the day then to the gunshop till 9-10 pm and I was able to take in a few things.
After moving to pursue my Doctorate, I no longer had access to the tooling. several years later buying and selling lathes and other machines, I learned what I liked, learned how to better run these machines, and ended up with what I have today. Probably $15-20K in used machines and tooling and I just do this as a hobby for myself now. Not exactly a cheap startup. Granted, you can start with a decent used lathe and some basic tooling. You soon learn what you like, what you don't like, and the capability of your machines. I got into it myself originally to save $$ by doing it myself because I couldn't afford to pay someone else to do it. I've built about 50 custom rifles for myself and a few others so sooner or later it pays off, but takes a while.
You can also learn a lot from some of the more reputable gun builders on many of these forums. Sometimes it takes a while to sift through all the BS, but many of these guys have in the past posted on set-ups, procedures, have decent discussions of various topics, and you can gain a lot from that. Just takes time to find it. Learn who some of these guys are and take all advice with a grain of salt. Every time I read about a certain procedure or set-up, I think about what they are doing. Is it better, just as good, does it make sense to me, or not up to what I feel is the best way to do it. Several ways to chamber a barrel and many of them can produce very accurate rifles.
That first 308 Norma hunting rifle I chambered was done with the muzzle in a 3-jaw, steady rest, and the reamer held solid in a Jacobs chuck in the tailstock. I saw barrel after barrel shoot no worse than 1/2 MOA being done that way, tight chambers too! Most of these were hunting rifles. I also saw countless BR accurate rifle too done this way! I don't chamber that way today, but goes to show, different methods work.
I think you are on the right track, finding someone to help you through the process and you will be leaps and bounds in front of someone trying to figure it out on their own. All those little crumbs of information that you get told while working with someone else that knows what they are doing are invaluable and will save you time and money down the road.