Monitor for power Mac G3 266MHz

Assuming that your G3 hasn't been upgraded with a PCI graphics card having a (PC-type/VGA) HD-15 display port, you're using the onboard graphics port with its DB-15 port. A Mac-to-VGA adapter would be needed, if you plan to connect a third-party display to that port. The next obstacle to overcome is the onboard graphics chip's lack of support for newer flat-screen displays with a widescreen aspect ratio. These aspect ratios didn't exist in 1998 and aren't programmed into the graphics chip's ROM. I'd suggest going to a computer reseller or thrift store and looking for an older/used 4:3 aspect ratio flat screen display, so the onboard graphics chip has a better probability of supporting its native resolution. A widescreen display will have an incompatible native resolution, resulting in a distorted image. Some time back, I recommended the same solution to another user in the same situation. He reported back that he bought a used Dell, either the P170S (17") or P190S (19") from a PC reseller and it was just what he needed.

Do you want to use the G3 or are you primarily concerned with viewing/retrieving files? If that's the case, the internal hard drive could be removed and connected to a newer Mac using a USB-to-IDE adapter (with included power supply). These aren't platform-specific and can be purchased at any store selling PC peripherals.