Okay, so when you say "depot" are the buses not just lined-up outside Magic Kingdom? And is the TTC easy to find? 8 newbies in Disney world may be a little overwhelming, we're not big travellers
Thanks!
The TTC is directly across the Seven Seas Lagoon from the MK and right next to the Poly.
At the bus depot outside of the MK main gates you only will find buses to the WDW resorts. To get to the TTC, you can take the express monorail, which runs counter clockwise around Seven Seas Lagoon and stops only at the TTC and MK, the resort monorail, which runs clockwise and stops (leaving the MK) at the CR, TTC, Poly, GF and then back to the MK, or the ferry boat, which goes back and forth across the Seven Seas Lagoon between the TTC and MK. Leaving the MK, the monorails are to the right and the ferry dock is to the left.
Once at the TTC, you can change to the Epcot monorail to get to Epcot. If you're on one of the other monorails, this requires going down the ramp from the resort or express platform then following the signs to the Epcot monorail platform. From the ferry dock, you head up toward the parking lot trams and will come to the monorail platforms on your way there. The bus depot where you can catch a bus to AK or MGM is on the parking lot side of the TTC.
At the other parks, buses to the parks pick up and drop off in the same bus depots as the resort buses. (Except for Epcot to MK, which requires a monorail to the TTC, etc.)
There will be signs directing you to and from all of these different areas that should make it clear, and there always are cast members around to ask for directions. So don't worry! You'll do fine!