The best pistolsmithing books available are the Jerry Kuhnhausen series.
These are gun-specific, with volumes on the Colt 1911 autos, the Colt Python-type revolvers, the Colt King Cobra types, the S&W revolvers, the Ruger's, and the Colt Single Action.
There are also volumes on several rifles and the Remington shotguns.
These books were written as a training aid to teach new pistolsmiths how to work on specific guns.
Although the books assume that you have the basic skills, and don't go into details on HOW to operate lathes or milling machines, this is an excellent way to start you training.
Again, Brownell's have some of the older general gunsmithing books, and these typically cover a range of techniques like filing, soft soldering, silver brazing, stock work, etc.
One word of warning on the older gunsmithing books: These were written back in the days of the "get it to work" school.
In those days a man's labor was cheap, but parts were expensive and VERY hard to get.
So, most of these techniques involved heating and bending, building up parts, and in general using techniques no longer acceptable.
Read these books to learn the various methods of working metal and wood, and the general methods used in gunsmithing, BUT follow the methods in the Kuhnhausen books.
Kuhnhausen was a fanatic about doing ti "The RIGHT way", which is usually the factory way.
Since Kuhnhausen actually trained gunsmiths, he focused on doing work the factory-recommended way, and restoring a gun to factory specs.
Today, parts are plentiful and fairly cheap. Using the old "shade tree" gunsmith's techniques are no longer acceptable. Although these methods will get the gun to work, they aren't RIGHT.
Follow kunhausen's methods, and you'll be doing it properly.
When you order a Kuhnhausen book from Brownell's, they will send you a free catalog of gunsmithing tools. Another source of tooling is Midway in Missouri.
Get both, and look over the book selection.
After buying a Kuhnhausen book, you'll have a better idea of what tools to buy.
To start off, the MOST used gunsmith tool is a good set of gunsmith's screwdrivers.
The Brownell's replaceable tip Master set is the best screwdriver made.