Riker:
Couldn't have said it better.
My recommendation: Start off with 20g carbs/ed or less. Use ketostix to monitor your progress.
Because food has hidden carbs you are bound to fuck up, and the next morning you'll wake up thinking SHIT, the bbq sauce on the chicken had 5g more than I'm allowed to, I wonder if I'm still in ketosis. That's where you piss on the strip and see that you're still in, and that's also how you'll gradually find out how much you can tolerate.
I personally can handle up to 50g - that's a lot more than most bros, maybe cuz of my metabolism, maybe cuz I do more cardio than most, whatever. The point is EXPERIMENT, see what works and what doesn't. If you do fuck up make sure to keep taking measurements, you may find out you're more tolerant than you thought. You may also find things you don't expect that kick you OUT of ketosis (aspartame for some (not me)), etc... just make sure to keep monitoring your readings. As Riker said, the WORST thing you can do is be at the 60g or whatever, with really low carbs but NOT be in ketosis - that just plain sucks in every way.
Also, carbs right after a workout are not as bad as carbs, say, first thing in the morning (has to do w/ glycogen depletion).
I could go on forever, but the point is, monitor your progress and see what works for you. On a CKD you have a "carb-up" day, which is what got me through those 6 grueling days - I had a poster of Papa John's in my living room to remind me of the award awaiting me at the end of the week. Try it and let us know how it goes.