So you want retro cred, modern gaming with old hardware or even perhaps (maybe) an edge?

What to know:

Q. Can I just plug it in?
A. Sometimes, basically, yeah. Ideally a vga connector makes things go easy, but MOST DVI outputs have an analog channel, making the cheap adapters work perfect. The Digital to Analog adapters are a mixed bag and range from un-noticable, to noisy. HDMI is the worst case, but varies widely by mfg, sometimes leaving you with only a few predefined video modes.

I have not yet explored the HDMI issue much, but it is almost always going to add some lag. Some adapters are configurable/hackable for different modes, but many are stuck with the broadcast standard set. I would advise to seek out DVI if not VGA ports whenever possible. DV i am completely ignorant of, it may contain an analog spec, but likely it will just be a bit better than HDMI and only do digital with your implementation.

Use a GOOD cable! Don't settle for some tiny thin, poorly shielded crap you happened to find in an ancient bag of dell freebies a second longer than you need to. The artifacts, ghosting, and weird contrast IS ALMOST ALWAYS THE CABLE. Search high and low for a thick white/beige one the thickness of your thumb, with ferrules (bumps) on each end to cut down noise. This is one area not to skimp at all. A $40 cable for a "free" crt is a wise investment as odd as it seems. Attach it well, make sure a thumbscrew on each side is tight if possible. Bad grounding, which happens through the barrel of the connector, is a common image issue.

*FUN FACT*
CRT's have no Native Resolution!
While some will look better than others, generally most resolutions will look equally good with no up- or down-scaling. This means that setting up what your OS thinks your CRT can do is super important!
Most OS's have pre-selected modes based on what is common. Many will suit you except for the refresh rate. Flicker, a common complaint in the CRT era, was actually a product of lower than optimal refresh rates, that a majority of displays had no problem achieving! At 50 to 60hz, the default (or max!) for most systems, the flicker gives me a headache after a half hour or so. Bumping it up to 75hz almost completely fixes it for all but the most sensitive, and by 85hz it is indiscernable.
But we can do better!

To produce an image, a crt SCANS A GODDANM ELECTRON BEAM ACROSS THE BACK OF THE GLASS, illuminating each pixel with a pulse of PURE FRICKIN ENERGY, exciting a phosphor lining, which glows for a split second when hit. His is all perfectly timed and adjusted to hit 3 different areas (Red, Blue and Green) and happens as a continous stream of 1000s of Zs, with (generally) NO processing of the signal, staying analog the entire time. This means virtually zero lag from the video card to your filthy eyeholes. Wicked.

Anyway, with the bro-physics explained, what you need is a copy of your monitors manual or spec sheet. The actual spec, not the cnet archive bs. You are looking for the max V(ertical) and H(orozontal) frequencies. often called Vfreq, sync range, etc. Thats it. From those you can extrapolate what refresh and video modes you can run at. Many CRTs can hit 2k at over 80hz, and hit over 150hz at lower resolutions. Use this with your OS, or video card driver (xrandr in linux) to reveal your options. Usually the V-freq represents your max theoretical refresh. The real refresh is a tad bit lower usually, i I rec backing off 10% for low res up to 50% when pushing HD. You can look up known good configs online or experiment yourself. Be SURE your program has an auto-revert function if screen becomes garbled when changing.

(I will update this when I find a non-shady site to do the math, or lay out the math for you)

Yes, yes they do.

Now start reading up on how to make Chrome, Firefox, and all your OS's and Apps see more than 60hz. Most are limited due to that ancient standard i refrenced earlier, and the long-debunked console-plebish refrain of 'you cant see more than Xhz'. *eyeroll* Blurbusters is your friend for checking out the effects of different settings. Once tweaked, you should be rocking OSU harder than a meth-head in a hammock.

I hope this info helps some TOOBNOOBz get into the arcane art of radiation-gun worship.

Please chip in obvious stuff I may have overlooked that you want to know, or stuff you found useful when starting out.

I will do a diff guide on where to look soon, time permitting. Stuff like what to look for, etc. Basically a used CRT buyers guide. For now the basics are:
1. Look at the back, what ports does it have?
2. Plug it in, does it work?
3. Google that P/N! Does it do the modes you need?
3b. What modes do you need? (vintage console or modern pc?)
4. Pay the man a case of beer and/to let him help you load it into your hatch.
5. ???
6. Profit!

Happy Gaming!