This came in as a comment but the advice is so good I decided to post it where everybody can see it instead of hiding it in the comments.
Before starting any work I suggest you perform safety and function checks to see what may need improvement.
You can familiarize yourself with procedures that may come into play by checking commonly available videos or gunsmithing DVDs. I shouldn’t have to remind you not to trust everything you see on yowtube…
You NEED the Kuhnhausen books.
You will also want a decent bench vise, maybe some jaw pads too.
Bench block, punches, and a small hammer. SMALL HAMMER. If you need a big hammer, you’re doing it wrong. Note pins on a 1911 as well as sight dovetails are directional.
Files of various shapes. I prefer Nicholson files. A copper penny applied crosswise across the teeth will remove loading.
A couple of stones of various shapes, both India and Arkansas.
A Dremel tool will come in handy for polishing, but can be tricky when used for metal removal. As with files you will want some practice.
If you are going to do trigger work, buy the hammer and sear jigs from Brownells, some feeler gages and some frame fitting pins.
This might be a good time to install a set of springs- cheap insurance, and the old ones as spares may come in handy.
Later you may want to acquire specialty tools such as sight pushers etc.
If you have an experienced helper the first time out you may avoid costly or dangerous fuckups, and gain confidence in your work.
Read and understand the books before you begin. Go slow, follow the instructions carefully. Pay particular attention to reassembly. And for God’s sake do diligent safety checks as prescribed.
This is not difficult work but requires attention to detail, so avoid distraction. Do your homework.
I do not recommend amateur attempts at frame rail fitting, Barrel/bushing/hood/link fitting will pay bigger dividends.
Don’t weld your gun unless you’re damn sure you know what you’re doing.
Be aware that “drop-in” parts may require fitting and WILL require safety/function checks.
I want to throw in my two cents worth too.
Buy the right tools. I was fortunate that I was working in a machine shop when I started working on my own guns, so I either already had the tools, had access to them or could make the motherfuckers.
Not only can you fuck something up quick with the wrong tools, but the right tools make a job so much easier.
Something else to keep in mind, especially when removing metal, if you fuck up the frame you’ve fucked up the pistol. That’s the part with the serial number, something to be concerned about if you live in a registration state.
Youtube can be your friend here but like the man says, don’t trust everything you see there. I’ve used youtube several times, but I always use reputable sources. For instance, I put a Geissele trigger in my AR. Before I even started a job as easy as that, I went to youtube for a quick tutorial – it’s a $225 trigger and I didn’t want to inadvertently fuck it up. There were 3 or 4 videos to choose from, one by Gary Geissele himself and the rest from amateur gunsmiths. Guess which one I watched.
If something is happening with your firearm that you don’t understand, go to a forum. It’s a tool that’s available, so use it. Ask somebody. If you don’t get a solid answer, you’ll get enough leads to put you on the right track.
And take your time. Go slowly. You don’t fuck shit up as much when you’re taking your sweet ass time and double checking every step and measurement.