So, playing a 1/2 game at my local casino..delt 88 stack is roughly 100bbs effective, villain (solid player, isn't raising too light, c-betting often, folding to 3bets a reasonable amount, not especially loose or nitty) opens to $12 (standard for this game), 3 callers in front of me, I call.

flop comes 679

preflop bettor bet out $20, folds around to me, I call with middleish pair + OESD. Villains c-bet % is incredibly high, often will show up with A-high, but overpairs are distinct possibilities.

Turn is 6 villain bets out $22..I call. Again, unlikely to improve the villians hand, still have OESD outs against overpairs, villian is strong enough player to double barrel with air/semi bluffs.

River is 8 villain bets 50..I have roughly 150 remaining.. A) whats the move and b) was the hand played well up until this point?

A) Shove
B) Yes. [Although I may raise flop depending on how you're playing]
C) Lol at results.

On the flop you can i) flat call as you did; ii) min raise/fold hoping to buy a free turn card; iii) raise and commit. All are acceptable plays. It just depends how much variance you can withstand. As a beginner, I would recommend you choose i) or ii) because you probably wont be good at dealing with variance.

Once the turn card comes the only thing you can do is call because he either has a very weak hand or a very strong hand.

On the river it looks like he either has a strong hand (e.g. a straight) or a very strong hand (e.g. full house). The only thing you can sensibly do in this spot when he bets 50 into 150 and you have 150 left with the third nuts is shove. He will pay you off with worse hands far more often than he will show up with quads. His play is entirely consistant with having quads but this happens so rarely that if you don't shove here you're losing value in the long run.

Your range is wayyyyyyyyy off vs most villians

a) You might be able to call the flop - but it is protected by being a 5 handed pot - so his c-betting range should be stronger. If he is an auto c-betting - ok.
b) Board texture should disincline villians from c-betting 976 connectivity and smashes flatcalling ranges
c) If you make any of your outs - you will have a 4 straight board so your implied odds are heavily discounted.

Turn

Bad barrelling card.......you can easily have many 6x in your range.........You prolly still dont have direct odds to call.......even though its a chronic underbet - but I have not bothered with the EV calc might be close.

River - I play river same way

p.s re your comment on he has semibluffs in his range - you have two 8 which makes it a tonne harder for him to have a semibluff.