The HP LaserJet 3550 has a USB connection. If you have an HP LaserJet 3550N, it has an Ethernet network connection.
HP's solution to connecting this printer to a wireless network is the
HP Jetdirect ew2400 802.11g Wireless Print Server (J7951G)
Unfortunately, HP wants $199 for it!
Any wireless print server should do the job for you. You can buy a
D-Link DP-G321 Wireless-G Print Server for $81.43. That's less than half the price of the HP print server.
Just hook the USB cable from your LaserJet 3550 to one of these print servers and configure the print server for your wireless network. You will be printing wirelessly from your notebook in no time.