My cynical side says 'prepare yourself for disappointment even if you are connected'. My experience says that FM Inc is carried away with their own PR suggesting that everything 'just works' between FM Client and Go. You'll see lots of snazzy marketing shots of an iPad showing product images in a catalogue, for example, or a Field Engineer taking shots and loading them into a database. Yeah... not quite as simple it looks.
The first thing I would suggest you tackle is getting images linked by reference in any FM Go file. (Embed the images in a file and its size will explode.) Then figure out where those images can be linked from. Then figure out a way to synchronise those images (outside of Filemaker, presumably) with the originals. In other words, so far nothing at all to do with Filemaker. We set up something similar with FMGo + Vs11 and were very disappointed to see how limited were the locations that any app on the iPad can access. I haven't tried the 'External Storage' function in Vs13 yet, but I can't immediately see how that would solve the fundamental limitations of the iPad. (You could avoid some of those limitations by simply using a laptop or Windows tablet, of course.)
The temptingly perfect solution, I believe, would be to store the images in Dropbox and have the Client file reference them there, then have the iPad link to the same Dropbox, and there you are. However our frustrating experience, from memory, was that the iPad can link to very little else, including a Dropbox folder, although using the Dropbox folder as the conduit between the 'server' images and the iPad's images would probably have been the most likely solution.