Taking care of your printer isn't complicated, but it's one of those things people put off until something goes wrong. A little routine maintenance goes a long way toward keeping your machine running smoothly and avoiding expensive repairs or replacements down the line.
Start with the basics. Keep the paper tray loaded with decent quality paper and store extra reams somewhere dry. Moisture is the enemy of clean paper feeding. If your pages are jamming more than usual, that's often the first thing to check. Swap in a fresh ream from an unopened package and see if it helps.
Toner cartridges are designed to be replaced when they run out, obviously, but you can extend their life a bit by removing the cartridge and gently rocking it side to side when prints start looking faded. This redistributes the remaining toner and can buy you another hundred pages or so. Don't shake it hard though, you'll make a mess.
Cleaning the inside of your printer every few months is worth the 10 minutes it takes. Dust and paper fibers build up on the rollers, the corona wire, and around the toner area. Most LaserJets have a built-in cleaning cycle you can run from the settings menu. For manual cleaning, power down the machine, open it up, and use a dry lint-free cloth to wipe down the accessible parts.
The fuser assembly is the one part that wears out on a schedule. Manufacturers rate most fusers for somewhere between 50,000 and 200,000 pages, depending on the model. When prints start coming out wrinkled or with toner that smudges when you touch it, the fuser's usually the culprit.