Also remember that you will never need a big enclosure for it even when its full grown. An adult female BP of 4-5ft will still prefer an enclosure no bigger than a 20-29 gal tank. Some people use something as big a 40gal breeder which is a reptile tank that is deeper than it is high and has a sliding screen top. These are fine, but always have 2 identical tight fitting hides so the BP feels secure in its enclosure. Just use the search option in the husbandry area of the forums. Search for enclosure, tank, set up, aquarium, pics, etc.. You will find threads with pics and more info so you can see what the care sheet is talking about.
Be sure to get a thermostat to plug the under tank heater into. This will control the temperature. Get a UTH that is about 1/3 the size of the bottom of the enclosure. Pick up an Accurite Weather Station from walmart. Its by the thermometers in the hardware section. Its a small grey unit with a big digital screen. They are very affordable. You place the unit in the enclosure on the cool side and the probe in the enclosure on the hot side directly on the glass/plastic over the UTH.
The probe for the thermostat which controls the UTH should be firmly taped right on the UTH under the tank. Then just adjust the thermostat until you have a hot side of 90*-92* and a cool side (ambient temp) of about 79*-81*.
You will love your new pet. Be sure to post pics and welcome to BPnet!