The FTDI FT232RL chip on the Nano is only powered if the board is being powered over USB
The schematic and your observations indicate this is not correct.
I am curious why they would say that and then I am still able to get 3.3v from a only a battery connected to Vin.
Simple, either the documentation or the schematic are wrong, not an unusual situation for Arduino and in fact most open hardware products.
Could you tell me a little more about carrier PCBs?
It's just a term I used for a PCB that holds your two modules (Nano and Xbee) and all the other stuff you have.
I'm afraid I wouldn't have a clue where to find "PCB design 101" tutorials, the board you would do sounds pretty simple but I admit probably not for someone who's never done one. I would have to hit Google the same as you but for a different reason, that being I had to learn that stuff a long time ago (before there was a Internet) and have no knowledge as to the location of such things.
I would suggest you download a copy of Eagle or one of the other free programs and start playing. You will have to enter your schematic first, then you feed that to the PCB part of the software and start laying out tracks. If those components have unusual footprints they may not already be in the program so you will have to design the pad layout for them as well.
It's not rocket science but does take some time to learn, be prepared for some very
Maybe someone else here can point you to some good tutorials, also the Eagle site (http://www.cadsoftusa.com/
) may have some.
Once you make a start there are plenty of people here (myself included) who can advice on specific design issues and review the design.
Another option may be to post on the "Gigs and Collaborations" board, there are quite a few members who do design work for people.