Use RTINGS.com, they have measured data for hundreds of monitors and they tend to explain the more technical bits.
other websites with harder to parse info:
if you care about gaming:
- Look for decent refresh rate (120hz and up)
- Look for Variable Refresh Rate
- Freesync is almost everywhere in gaming monitors, G-SYNC is a nice premium
- Response Time and Input Lag should be low (less than 10ms would be nice)
if you care about good picture quality:
- Look for NATIVE contrast ratio
- at least 1000:1, 1500:1 or up recommended
- Look for the Pre-calibration Color dE
- anything more than 5 is garbage, less than 2 is great, less than 1 is pro-grade
- (Extra) Look for HDR and color depth (windows support for 10bits kinda sucks tho)
in any case:
- Make sure it's Flicker-free (no PWM in backlight)
- VESA (Wall Mount) is a nice extra if you want to get monitor arms in the future
- Always shop for the exact model number, monitor brands pull stupid stunts where different sizes or model names are completely different.