Originally Posted by
Eastbay1K
If you are even slightly able-bodied, walk (especially prior to such a long flight). The airport is essentially a ring, so even if you go the wrong way, you'll end up in the right place. When you leave the secured area of T-1, make a left and follow the signs to the int'l terminal. The part that says Main Hall will have your check-in counter, and there will be electronic signs at the end of each row that will tell you which row your airline will be at that day. After you check in (and do so, even if you've received a BP @ATL) you'll be directed to the security checkpoint for the G gates.
While I agree about walking (especially before/after spending so much time sitting down), it's important to note that if you want to talk from Terminal 1, boarding area B to International, boarding area G, you will have to leave security and reclear.
There is, however, an option: as long as US is still in boarding area B, you may be able to use United's transfer shuttle from Gate 39 (in boarding area B) to International G. The bus will deposit you either in G or in Terminal 3, boarding area F, which is connected to G behind security. Terminal 3 is also home to a number of excellent food options, and might be worth the diversion if you have the time.