Yeah man, depending on how hard you ride there are daily, weekly, and monthly checks. Modern bikes probably don't have the need for the maintainence overkill the old bikes did, but they are good habits anyway:
Daily:
Tire pressure and condition, brake function, headlamps and signals.
Weekly
Lube Chain, inspect gaskets for leaks, seals (brake reservoir caps too!), oil level, chain slack (no more than 1 inch while sitting on bike), inspect hoses and lines for cracks. Inspect fork seals, chain and sprockets for uneven wear (sign of misaligned rear)
Monthly
Check for loose bolts and screws, Check air filter, change oil, inspect battery. If possible, check spark plugs too.
Its a lot to do, most people don't do it, but its some good habits. I'd be lying if I said I kept to this list. But I do a walk-around inspection before I get on each time and check for things that aren't right (low tire pressure, loose parts, chain condition, brakes and lamps). I have been through a lot with my old dinosaur bikes from the early 80's, from losing shifters on the freeway to headlights burning out on an unlit highway.... to even running over a dead deer! You assume a lot of risk riding a bike, the best you can do is manage it. You have control over the condition of your ride, so do all you can. You never know you missed something until it gets you at the worst moment possible.....