The Rise of the Tomb Raider header image is courtesy of the talented OtisInf.

• Limits: 3 screenshots per post. If you have more than 3, make more posts or use thumbnails.
• Spamming: No more than 2 consecutive posts of the same game. Link to an album of your collection.
• Naming: Always include the name of the game with the screenshots. In case you downsample, report the resolution which you downsampled from.
• Compression: If it's visible you will be called out. Follow the JPEG guide below.
• Emulators: Emulator screens are fine. However, you should list the emulator used.
• Stretching: Do not post stretched screenshots. Do not take 2.35 screens unless you know what you are doing.
• Spoilers: Please do not post major plot points from games released in the last 2 months.
• Thinking: Think before you post. Is the screenshot really worth posting? Does anyone care about some ugly texture you found? No.
• Feelings: Did someone hurt your feelings? PM a mod. Take your drama elsewhere.
• Size: Be a good sport and DO NOT post full size 8-16K+ PNGs, some have limited data plans.

CSS Image size tweak for Opera/Chrome users: First and foremost, a small edit to this site for a much better screenshot browsing experience.
• Custom Resolutions: If you have an Nvidia or an AMD card, create a couple custom resolutions over 1080p, preferably 2160p.
• Steam: You can tell Steam to take lossless screens and output them to a custom location when hitting the screenshot button.
FastStone: It's free and quite easy. You can resize a whole folder with different options and convert to .png/.jpeg.
Irfanview/Photoshop: Use one of these to convert to .png from .bmp, crop out black bars or resize pictures.
Zoner PS: Another Photoshop alternative, recommended by Angelus Errare.

Flickr: Two terabytes of storage and great for screenshot library management.
Picpar: Brought to you by none other than X3sphere, a simple and efficient image host.
Abload: Easy to use, doesn't compress jpegs further, auto-converts bmps to png nicely.

Credits for the OP layout go to the great Stallion Free.