Great advice from Canucklehead. A strong posterior chain will help you on so many levels.
Here's a rough idea and a few thoughts on my training this winter:
Lots of trap bar deadlifts. A lot of people agree that it probably has the best "real world carry-over" of any gym exercise. It's not that technically difficult, chance of injury is fairly slim (with decent technique) and you can lift a loft of weight with this one. A good guideline is 2X your body weight for adequate strength.
I also really like the Jefferson deadlift. It's a bizarre looking old school lift, but addresses rotational aspects more than other lifts. It's great at ironing out asymmetries and can be used to rehab back (especially SI) issues. Just google Dellanave Jefferson deadlift for a tutorial.
Those are the only lifts I'll be doing for strength. Keeping reps in the 3-5 range typically.
For upper boy, I'll focus on push ups (typically on rings), pullups and inverted rows (with rings).
I'm also going to experiment with the Pallof press to address rotational strength. I'll also look into jumps and medicine ball throws too.
I'll do strength work 2-3X per week.
I've got a bunch of Kettlebells at home and will do a few swings and Turkish Get Ups most days. If you've got any shoulder issues, Turkish Get Ups are a fantastic way to rehab them.
I'll do mobility work daily too.
That's the rough plan. I'll update more as I progress.