First, you need to get the signal from your deck (receiver/radio/whatever) to your amp... normally this is done with RCA patch cables, which send a relatively clean low-level signal for your amp to amplify. If your deck doesn't have RCA outputs (likely if its factory), your amp will need to have speaker-level inputs, then you can use speaker wire to connect the two. Once you have your deck connected to your amp, wire all your speakers (4 I'm assuming), to your amp, connect a power and a ground cable, a remote turn-on lead, and you're set. =)
Keep in mind that to have all four speakers to your single amp, it needs to be a 4-channel at least, you didn't mention how many channels it has so this is very basic info.
Power: a relatively thick wire (depending on wattage of your amp) needs to run from the amp to the positive terminal of your car battery, usually poke it through some hole in the firewall, pull it through under your dash, and run it under your carpet to your amp (presumably in the trunk).
Ground: you'll need a wire the same thickness (gauge) as your power wire as your ground wire... this connects from the ground terminal on your amp to your vehicle's chassis (usually a seat belt bolt makes a good ground point, make sure it's clean of all rust/paint)
I've probably left some, okay, quite a few questions unanswered, but this should give you a basic idea of what you're going to have to do. =)
Good luck...
