I know this is basic, but so is my game at this point.

1/2 NL at Local Casino

I start hand with 300.

Hero is UTG +2 with AdQc I raise to 8.

Get called in three spots. HJ (250ish), Button and BB.

Flop is Ac 9c 5h

I bet 26. Get called by HJ.

HJ has been solid in short time I have seen him play.

Turn is 6d. I bet 50. HJ raises to 100 and I fold.

Thoughts?

Preflop?
Flop? (good sizing?, should I check?)
Turn? (Potcontrol check?)

grunch: flop - fine. turn - probably fine.

going by your read of villain as "solid" b/f is probably the best line on all streets with top pair, assuming you haven't seen villain bluff or attack when he senses weakness... i think your pot control is good. i may have even checked turn, but would depend on how much i weighted the flush draw.

i don't think this is basic... it's a tough spot... it's a regularly seen tough spot... but it's still a tough spot. this is where getting better at "reads" will separate you. put him on a range. would that range include draws? would it include bluffs/pure aggression? see how accurately you ranged him after observing him further.

Pretty standard.

Your odds are really good on the turn with a pretty good hand, I might take one off and see the river.

oh, and to answer your specific questions

imo... flop sizing is good and definitely c-bet it. you have top pair good kicker and there is a flush draw. if you didn't hit at least top pair i would probably not have c-bet into 3 others.

turn is tough to say about pot size but i think it's good for pot control reasons and being out of position.

the question in terms of pot size that comes to mind here is spr. you're getting close to being able to shove. if you had called or raised the turn... i would consider you "committed". and i think i fold like you against a non-spewy player.

SPR is a flop concept, not a turn or river one. So be careful using SPR as commitment threshold in this spot.