If your printer is fairly recent, then it may be compatible with the iPad's built-in AirPrint feature. If not, then you're stuck using third-party apps, which broadly come in two flavours; a stand-alone iPad app that connects directly to your printer, or a Mac/PC app that acts as an AirPrint print server for your iPad. Of course, there are pros and cons to each approach...
With the stand-alone iPad app (e.g. PrintCentralPro) the document you're printing has to be opened in that app, which in my experience (with PrintCentralPro) can be a bit convoluted (it's also the fugliest iPad app I've ever seen) and obviously you'll need a copy of the app on each iPad that you want to print from.
With the Mac or PC app (e.g. Fingerprint or Printopia) printing is very straightforward, but the app has to be running on a connected computer for it to work, which may be an issue if you're just trying to print something quickly from your iPad without switching on your home computer. OTOH you just need one copy of the app on the home computer for every iDevice in the house to be able to print to it.
FWIW I tried both approaches and settled on Fingerprint running on the old iMac that we use as a home server, and it works a treat.
HTH Pete