It's nice to see people with a similar background as me on here, CoachQ's given some great advice. I'm an ACE certified Personal Trainer with a BA in PE (Exercise Physiology), I work at a personal training studio full-time and work with everyone from high school athletes to people in their 80's, and everyone in between. I do work with a couple of the local pro athletes and a nationally ranked HS athlete. I don't have time right now to go into a general disc golf workout routine, everyone is at different training levels and unique anyway, but I can give some basic advice.
-If you're a beginner you'll want to start with 1 exercise per muscle group (chest, back, shoulders, tris, bi's, core-abs-lower back, legs) and perform 2-3 sets of this exercise. Target 15-20 reps as a guideline, 2-3 nonconsecutive days per week.
-Start with machines for the upper and lower body muscles at first, if you're positioned right on the machine it guides you through the form and is one less thing to worry about.
-Always perform the lift slowly, a pace of about 3 seconds on the way up
and down is acceptable, never less though.
-Learn the proper form for the exercise and never compromise it to get a few extra reps, IE arching your back, swaying your arms, using momentum etc. Look online at some of the professional websites on how to do things right or ask a trainer at the gym. Oftentimes the biggest gorilla in the gym has the worst form, be careful who to trust.
-Target a certain number of reps but use it as a guidline, go to muscle fatigue but not failure. If you're going for 15 reps don't sacrifice form to get there-stop when your form starts to falter. If you get to 15 reps and you're still not tired, don't stop but go until you are tired. You don't need to go to total failure but the muscles should be burning.
-Avoid higher risk exercises when starting out such as barbell squats, lunges, dead lifts and power cleans. These are advanced exercises and require additional technique and training. These are also easy exercises to injure yourself even with good form.
-Warm up for a few minutes and stretch beforehand, stretch when your finished as well. Stretch to you feel tension and hold for 10 seconds or so.
-Cardio is great for your heart and endurance and is something everyone should do at least a few time per week
-No pain No gain refers to muscle fatigue not injury. If you're muscle are fatigueing you'll feel a burn that will intensify as you get closer to muscle failure, if you feel a sharp pain particularly in one distinct spot or it doesn't feel right then stop the exercise. You so need to push the muscles but you shouldn't go to total muscle failure, at least often anyways, form starts to compromise and the risk of injury increases.
-Never hold your breath! Try to breathe out on the tough part of the lift and in on the easier part but Never hold your breath.
-It's always better to under-do it than over-do it, always have fun.