Heretohelp,
Your description sounds like you hardly do any upper body work, which would make you a "beginner" for these body parts you want to improve. You've received some good advice for a beginner and good advice for someone who is not a beginner (i.e. bad advice for a beginner). Let me reconfirm the good advice for a beginner.
First 3 months: Training the body for good technique and preparing the muscles for lifting
Month 1, Low weight, high reps: You will want to be able to complete 3 sets of 12-15 reps/set. Your focus is on technique. Your weight is sufficient to make you focus on your technique but light enough to complete all reps in the 3rd set without struggling. You will get your best value from a personal trainer during this section. The trainer will help you ensure your technique is excellent.
I recommend dumbbell bench/incline press, seated shoulder dumbbell press, lat pull downs, bent over rows, shrugs or upright row. Since you're not "building muscles" but "learning technique" you can work your muscle groups more than once a week. You should not be paralyzed with soreness because of your routine. You can increase the weight only if you can complete all the reps.
Month 2, increase weight and split up the first exercises, add complementary exercises: There are many ways to split up these exercises. Some recommend combining complementary muscles (bench press and shoulder press) some recommend combining the push/pull exercises (bench press and lat pull downs). You'll have to decide which you prefer. What ever you choose, you'll also add complementary exercises to these initial ones. Chest flies complement bench, lateral shoulder raises complement seated press, seated rows complement both lat pull downs and bent over rows.
You'll perform the new exercises low weight and high reps. Your old exercises will increase weight so you can only do 8-10 reps for all three sets.
Month 3, increase weight for both primary and complimentary exercises and consider adding bicep and tricep exercises. Don't bother with low weight and high reps for the new stuff. Target your weight so you remain between 8-12 reps. Increase when you get 3 sets of 12 reps.
Once you've finished the first three months, evaluate your results and see if you're getting what you want. If you desire more bulk, add weight and keep your sets in between 4-7 reps. If you like what is happening, continue with your 8-12 rep sets.