A 300dpi laser will serve you well if your printing needs don't extend beyond basic correspondence. Aim for 600dpi for complex output using graphics or small fonts. Look at a 1,200dpi laser for the sharpest possible laser image quality. Also, examine the few solid-ink printers if you're in the market for a colour laser. Confirm that any printer with upgradable memory offers the resolution that you expect it to with the amount of memory included.
Some printers require a memory upgrade in order to reach their highest resolution potential.
Confirm the length of warranty coverage for any printer you buy, plus the accessibility of technical support. Check if the manufacturer's Web site offers updated drivers and online help.