Most people don't install a network just to share printer or Internet access. It's based on some sort of software use. The first and foremost rule is that you must find out from that software vendor what network they support. Some may run on Windows 95, some may only be Windows-based. But if you don't go with what they recommend, and you have a problem, they won't help you.
Every copy comes with free, full built-in networking.
No matter what the client or workstation, chances are thay can connect to it. But it really depends on what you want to do . For Windows 98, if I want to let you see my files, and I want to print to your printer, it's a 30-minute job to install. It only comes wth an E-mail client, not a server. The whole point is sitting down and thinking about you want to be when you grow up.