If you are already using iTunes, it will do it automatically as soon as you connect your iPad for the first time. If you haven't used iTunes before, when you install it, it will give you the option to import all your music and photos into iTunes. Then, when you plug your iPad in, it will automatically put them all on your iPad. Extremely simple!
Now, if you don't want iTunes to put EVERYTHING onto your iPad, you need to go in and deselect the auto-syncing options before you plug your iPad in for the first time. I discovered this the first time I plugged mine in and it attempted to sync about 100 gig of music and 10 years worth of family photos onto my 64 gig iPad!
Edit: Oh, if you have wireless internet in your home, you can also let it do it automatically via wi-fi by using the sync to cloud features.