You should see some activity at about 24hrs. Trying to keep the fermenting beer at the right temperature and a thorough aeration before adding the yeast are keys to sucess for a good fermentation. Lager kits normally ship with non-lager yeasts (ale yeast) so fermenting at 18-21c would be about right, if however it's a 'proper' lager yeast then try to keep it cooler ~15c should do it.
Then.......patience is key as you have said....once it's bottled or kegged get another brew on quick, an empty fermenter is a lonely fermenter.
PP