Unfortunately, from my experience, once your little one decides s/he likes "real" food, there's little hope in going back. This also means you'll soon lose the convenience of feeding him yourself since he'll likely insist on doing it himself, whether capable or not.
So, where to go from here? Try cheeses, tender pasta, cooked veggies (green beans were a favorite starter for our boys), rice, soft/cooked fruits. Once he has some practice, consider tiny pieces of tender meat. Expect mealtime to get messier and more time-consuming.
Chances are, your little guy is more ready than you are to move on. At 8 1/2 months, he's probably ready to "mash" his way through a meal, and giving him "solid" finger foods will allow him to further develop his fine motor skills. The graduates type foods are convenient, but I find they're less than economical and not worth it for more than a few weeks, maybe a month. Those graduates "meat sticks" are disgusting to us adults, but from my experience as a parent & babysitter, the little ones like them a lot...
As for the left over baby food, don't give it away just yet. You may be able to "sneak" it into your son's diet yet. Take for instance that butternut squash (or carrots): add it to mac & cheese, and he'll gobble it up! (I still use this trick with my 3-year-old!) He may not be ready for meatloaf yet, but when he is, add a jar of green beans or peas to the meat. (Actually, Gerber had a recipe on the back of one of their cereal boxes that did just that, added cereal & some veggies to mini meatloaves.) You might want to check with your pediatrician before giving your son eggs, but if you get the greenlight on that, you can add babyfood (say, peas) to that as well. (What did YOU think was in Dr. Seuss' green eggs?!)
Canned fruits & veggies are convenient, but you'll get less sugar and more vitamins & flavor if you microwave fresh ones til they're soft. That's not something you'll want to do right before a meal, but it's good to do the night before, then just warm them a couple seconds to take the chill off. But consider peeling & cooking apple dices, peaches, carrots, beans (not just green!), asparagus, sweet potatoes, squash...
Don't get stuck on the puffs, but keep in mind his old favorites of the baby foods, and keep those flavors in his diet, just as "new" foods... If he's anything like our boys, you'll be amazed and amused by how well and how much he'll eat when you let him. ;)
Enjoy!
J.