What do you mean "done"? If it ages for several months, it is surely done. I'd suggest cold crashing before kegging if you can. This will compact the sediment to the bottom, minimizing trub in the keg, AND.....cold beer carbonates quicker!!! If nothing else, if you can't cold crash 1st, once you fill the keg, just throw it in the keggerator and let it chill for a day or so, then force carbonate it.
There are several ways to carbonate too, so be sure to check out details for that, to see if you want to FORCE carbonate or just set it and let it carb itself over time. It'll take a lot longer to do the latter though, I always force carb mine. Good luck!