Though many experienced brewers may read this and note that this is not the absolutely best way to ferment lagers, it is regarded as the most foolproof and that's what you are looking for for your first lager fermentation. You need the first batch to be a success to get hooked on lagers and their smooth taste. Then you may start digging deeper into this subject and find a fermentation schedule that works best for you and your set-up.
One day before brew day pitch a 2 qt (2 L) well aerated starter with an Activator Pack (Wyeast) or vial (White Labs) of the lager yeast of your choice. Both companies offer really great yeast strains. If you are looking for a versatile lager yeast go with the German Lager (WLP830 or Wyeast 2124; According to White Labs and Wyeast this is the W-34/70 strain which is the most widely used lager strain in German beers) or whatever your recipe calls for. Keep this starter at room temperature 68 - 70 *F ( 20 - 21 *C) and let it start fermenting. It may throw off some sulfur notes (rotten egg smell) which is common for lager yeasts.
Brew an average gravity lager OG: 1.044 - 1.056 (11 - 12 °P). These beers will not result in toxic alcohol levels for the yeast which makes for a more forgiving fermentation. Once brewed, chill the wort to a temperature below 60 *F (15 °C). The mid 50's should work best for this fermentation schedule. If you are not able to get the wort that cold with your chiller and your tap water, you can use a pump to recirculate ice water though the chiller. Because this pump doesn't have to be food grade, a simple submersible utility pump will do. Another option is to let the wort cool in your lagering fridge before pitching.
When transferring the wort into the fermenter, make sure to leave most of the hot break and hops in the kettle. This can be achieved with whirlpooling or straining. The latter can be problematic since the fine break material tends to clog the strainer. The removal of hot break, some cold break and hops is recommended because the beer would be sitting on this trub for a long time (4 weeks) although recent studies have shown that the importance of trub removal is somewhat overstated [Kuehbeck 2007]. After transfer into the fermenter the wort needs to be aerated well. A healthy lager fermentation requires more oxygen than an ale of the same strength in order to reduce the stress on the yeast. The required oxygen level of 8-10 ppm (mg/L) is best achieved though 1 to 1.5 minutes of pure O2 or 20-30 minutes sterile air though a 2 micron stainless steel stone.
Pitch the whole starter into the primary fermenter. Wait until you see fermentation activity (low kraeusen or bubbles in the airlock) until you move the fermenter to an area (basement or fridge) where you have a constant 48 - 52 *F (9 - 11 *C). Let the primary fermentation take its course for a few (3-4 weeks) until there is no airlock activity left. If you want to pitch the yeast cold (at 46 - 48 F ( 8-9 C), which is actually the preferred method, you will need to grow more yeast. This means using a starter as large as 1 gal. When pitching cold you can also expect a longer lag time. Because all these things complicate the process I'm advocating warm pitching for your first lager.
After the primary fermentation is complete, rack the beer to a lagering vessel. It can be another carboy or a soda keg with shortened dip tube. The beer is then moved to an area where the ambient temperature is between 32 and 38 °F (0 - 3 °C) where it will remain for at least another 4 weeks.
Now you can either rack to a serving keg and force carbonate, in case you didn't do the force carbonation during lagering, or bottle. If you plan to bottle condition the beer you may want to add fresh yeast with the priming sugar, because the yeast present in the beer may not perform as well anymore. After all, it is about 7-6 weeks old. A quarter to half a pack of dry yeast is the easiest way at this point. It also doesn't matter if ale or lager yeast is used since the flavor profile of the beer has already been determined by the yeast used for the primary fermentation. If you don't add fresh yeast you need to be more patient with the conditioning of the beer. Let the beer carbonate at room temperature or anywhere between. The higher the temperature is, the faster the beer will carbonate.