network for linux

At the first thank u for interested me about my inquires whatever.i'll download manadravia according to y advice in the my library for small network, there are 4 machines -at least- will working on internet in the library but i'm afraid of the linux don't support the internet connections and don't support my database and programs too which extension are exe , pls if u can give me some descriptions and requirements ( hardware,software) are neeeded for small network the library has a router 56 k 6 machinies ( pentium 4) card network And thanks for u