Retro computing is extremely fun and, sometimes, extremely nervewracking as well. However, with all its downsides, the fun of configuring old computers with old software and old peripherals is simply too good to pass up.
Installing Windows XP on all kinds of computers is my favourite odd thing to do.
The Higher Intellect Vintage Wiki is a good resource for old computers.
Surf the internet
You can browse the old net with protobrowser. It proxies requests to the internet archive and displays it almost seamlessly. Haven't yet tried it.
Old Software
Find old windows software from winworld