There are a lot of different ways to handle lagers. I honestly believe that if you pitch enough yeast, and pitch it into cool enough wort, then everything else will take care of itself. But Jim made the best point - let the yeast set the schedule. Don't rack or start lagering until the beer is fully fermented and has no diacetyl.
Personally, I chill down to 45F, then set my thermostat to 50F, pitch and let it sit for about 5-7 days. From there, I bump the temp 2 degrees every couple of days. I D-rest for 2-3 days at ambient (but at least 60F). It's not often needed by the time I get my fermentation temp ramped up, but a diacetyl rest gives me peace of mind. I also dry hop at D-rest temps if I'm dry-hopping a lager.
After the D-rest, I cold-crash in the fermenter for a couple of weeks. then I rack to keg and finish lagering under pressure. For a big beer like a doppelbock, I'll lager for maybe 4-6 weeks, then finish aging at cellar temps.