I'll be racing for the first time this year. I know a lot of people put new tires on every weekend. As a rookie, how often should I expect to put on a new LR/RR?

That depends on a few things.....what compound.......how abrasive the track is and how hard you run the car .
The tire that most use is either a Hoosier sp-2 or a 15.....a 12 may be too soft depends on the track . Stay away from the sp-3 ..it's a rock....it will last a long time , but like I said it's a rock.
but normally about 4-5 good races ...that's an average .
Don't know what the American Racer compounds are but they have some that are comparable....
Best thing to do is talk to the guy's at the track that you are going to run at to get a better idea

Thanks for the response, very helpful in preparing for the season. Any thoughts on a D20?

D-20 is just a little harder than a sp-2.....it would just depend on the track.....
we run a focus tire on the l/r (equal to a 12 ) and a sp-2 on the r/r .....
Also remember not all tire sizes come in all compounds .....get on the hoosier website or give them a call , they will help you out ...

Thanks, that is why I am asking. My only choices on the LR are D12 or D20. I have gathered that the track is usually pretty wet so I'm wondering if a D12 would be too soft.

If the track stays tacky I would run the d12 ....that tire does pretty well on the l/r...
But look and see what the guys at the track are using ...that will be your best indicator...

Thanks for your help! I will ask around.

Sp4 is a rock. Sp3 is the perfect tire for an abrasive track. Ran one quiet a few times this year when the track was too hard/abrasive for a 2 (we just kept blistering 2's).

Sp2 and sp3 for rr depending on track conditions
D12 is a great lr, I haven't ran a d20 so no advice there

In any sense, as far as life goes I was usually getting about 2 race nights on a RR and 3-4 on a left rear. Again, just depends on the track conditions and how "competitive" you want to be. Some people throw new ones on each night, others run them until theyre pavement slicks. lol

Where are you running? What series? Several of the mini sprint racers around here run American Racers. Andy Bradley is with MMSA and is full of great info and would be willing to help you out. Very few put on new tires everynight. Its just not needed.

Thanks!