I have received a couple of questions about this, and at least one thread request, so here goes.
Right from the start: Low-Carb dieting is not for everyone. The only way to know if you can successfully diet utilizing this method is by trial and error.
Ketogenic diet: This is the standard low-carb approach, where minimal (less than 10% of total kcal/day) are consumed. While this may work well for some, most athletes require more carbs than this.
Training would proceed as normal.
Targeted ketogenic diet (this is an older term, but the one I first used/learned for this approach, so I still use it): This method allows the athlete to consume a modest amount of carbs pre-/post-workout to either provide energy, replenish depleted muscle glycogen, or both. Amounts vary based on the individual, training intensity and volume, and sometimes even frequency of workouts.
Training would also proceed as normal.
Cyclical Ketogenic Diet: This is my personal favorite, largely because it allows me to eat at IHOP in the morning, and have pasta for lunch and dinner one day a week. How cool is that? There are various methods of accomplishing this, but I will detail the one that works best for me.
I train Westside-style:
Monday Morning: ME squat
Monday Evening: ME Bench
Tuesday: GPP Lower body
Wednesday: GPP Upper body
Thursday: off or light cardio.
Friday: Depletion workout (DE squat followed by DE bench)
Saturday: Eat and sleep. Lots.
Sunday: Off (sometimes I would do ME squat here, depending on how I felt).
Diet: Monday - Friday (pre-workout) as little carbs as possible.
Post workout: High glycemic carbs and protien for the first few meals. Goal here is to achieve glycogen supercompensation, and after a few I am actually force feeding myself, so liquid works best for me. Solid food immediately after either made me cramp or gave me trouble keeping it down. I used waxy maize starch (nice and cheap) and whey protein for the first two meals, and WMS and a protein blend (BSN Syntha-6) for the next two. During my re-carb (Late Friday through Saturday) I would, with the exception of breakfast Saturday morning (IHOP rules) I would keep my fat intake as low as possible, not only because fat delays gastric emptying, which defeats the purpose of trying to refill muscle glycogen as quickly as possible, but because the combination of carbs and fat is more likely to screw up the insulin response and cause spillover which can lead to fat storage. The goal with this approach is to get the nutrients I need to the places I want them to go. Sunday was a low-carb day as well.
There are a lot of variations with each approach. Some people would perform a TKD-style diet with a modest depletion workout, etc. Methods vary with the individual.
Good background reading:
http://www.mendosa.com/ (go to the section marked food, and read up on the glycemic index)
Keto Forum: http://forum.bodybuilding.com/forumdisplay.php?f=61
Great thread: http://forum.bodybuilding.com/showthread.php?t=59921
Thread: Low-Carb Powerlifting