What body parts do you want to work on? In other words, what hurts, tires, or cramps?
step two: pick a routine that will help you acheive that goal.
Go look at my basic routines for motorcyclists. Pick out the areas you identified in
step one. Those'll be your exercises.
step three: pick a schedule for that routine.
You'll want to do those exercises three times a week. They don't have to be the same three days every week; just don't work the same muscles two days in a row.
step four: ok, now grab those weights!
Each day you exercise, do 2 sets of 10 reps.
[A "repetition" is, bascially, doing one exercise once; for example, one push-up or one bicep curl. A "set" is a series of repetitions. For example, doing 10 push-ups at once is 1 set of 10 repetitions].
step five....and beyond?
You should at least break a sweat -- if you can breeze through both sets without thinking about it, increase the weight. Similarly, if you can't make it through two sets, just do fewer repetitions. Don't be afraid of heavy weights -- in my personal experience, fewer reps with a heavier weight is even more productive than higher reps with a lighter weight.
If you get bored while training towards your goal, simply examine your routine. Have you been doing two sets of lunges three times a week for six months? Try alternating them with squats or step-ups.