I've been an electrician for 19 years and specialize in control wiring
on multi-million dollar mining machines. I own three multi-meters, and each has its purpose. To best identify what you need in a multi-meter you need to understand what each function does, and some of the terms you might come across. If you need one for electronic circuitry troubleshooting you would require a precision multimeter, not the ordinary electricians multi-meter. If you don't solder printed circuit boards for a living, then you need one like the rest of us use.
Multimeters come in many shapes and sizes. I prefer a small version with a built in amp clamp meter. It helps to have several types of leads, the black and red sharp pointed ones and alligator clip style. I also recommend the purchase
of a hanging magnet clip if the multimeter you buy have them as an accessory. They really help, unless you are one of those lucky people with three arms. The most important feature you should have is an Auto shutoff. Auto shutoff has saved me countless times, as most digital meters can get turned on accidentally in there storage cases. This feature will guarantee you have a working meter when you need it most. Lastly I would make sure it has a illuminated display feature as you will find most electrical
problems leave you in the dark or in a dark area. Some even have an led flashlight built in.
Now, if you come across a True RMS meter, this simply means it has a more accurate AC voltage and current reading capability. This is mostly needed when trying to determine power factor corrections, and usually comes with a logging ability that 99% of you will not have any use for, and they cost substantially more. The general use multi-meters are plenty accurate enough for troubleshooting needs.
I could talk about brands for quite a while, but I would steer you away Fluke. I've owned 5 of them in one year, and found they really don't stand up to humid or direct contact with water
. Good Brands that I've used in the past are Ideal, Greenlee, UEI, Sperry, and my favorite Klein. Klein is the most preferred toolmaker of electricians and they make tools exlusively for electricans. I own two Kleins and one Fluke. My last remaining Fluke I use exclusively for over 600 volt testing. Be sure to never use a multi-meter beyond its voltage rating. Most are only good for 600 volts. Chineese no-name brands are usually 500 volts or even 250 volts. Look at your meter now and see what its rated for.
My other two meters are the Klein CL-200 , and the MM-200. The CL-200 is my workhorse. It cost about $50 and has proven to be the toughest meter I've ever owned and extremely waterproof. I work in tunnels all day and most often electrical machinery break down when exposed to water
seams (waterfalls). I'm always getting poured on and this meter is a steal at $50. It does everything I need except DC amperage. For DC 4-20mA signals I use the Klein MM-200, and have no complaints. Both have lighted LED screens and all the other Resistance, Continuity, AC/DC voltage, temp probe, diode test, and capacitor test functions as well as frequency and peak testing. Like I said all you will need, and both have the Auto shutdown feature. For $100 you can't go wrong.