The usual recommendation....
Make sure you get your RAM from a reputable dealer who tests and guarantees compatibility with your model Powerbook, offers a lifetime warranty and a no-cost return if it doesn't work.
When you are putting the RAM in, it goes into the socket connector-edge first at about a 30 degree angle. Make sure you apply a bit of pressure while at the 30 degree angle to seat it properly - there should be no more than 1/32" or 1 mm of contacts remaining visible, and it should be seated quarely in the socket. Then pivot it down to the horizontal position.
The proper sized Philips screwdriver is a must. Bear down with some pressure on the screwdriver to keep the bit in the screw as you are breaking the original resistance to moving. If it is tight, you don't want the bit riding up out of the screw and then turning.
The lower socket is a little crowded to get the module inserted at first, but really it's pretty easy.
Thanks
Trevor
CanadaRAM.com