Hmmm, where to start. Some things I've learned over the years about track days and racing (vintage).
Read every club's rules before you start spending money!
Get as much seat time as you can. Have fast racers ride with you, but make sure they drive the same type of setup as you do. A FWD driver will be useless if you have a RWD car.
Stock rods (no matter what you do to them have a short shelf life before they start to "stretch". Stock crank will last all day at 6,000, but 7,000+ is going to kill it sooner or later.
Lighten everything that you can and still be safe.
Stich weld every metal joint.
Put in a good radiator and new hoses. Buy or drill holes in the t-stat to let air through.
Adj strut rods
Get rid of rubber parts, except the trans mount.
Good shocks are not an option, but a requirement.
Roll/cut fender lips before painting!
Removable steering wheel or suffer the consequences.
If you go cheap on parts, THEY WILL BREAK...soon.
Ask lots of questions.
Lose the coil spring covers.
Use hood pins.
Put catch cans on the valve covers and the rear axle. Rebuild the toploader with good parts from David Kee.
Use Joe Gibbs/Driven MTF in said toploader.
Put a good locker in the rear. I've been very happy with the Detroit Tru Trac.
Put heim joints on the stock toploader shifter rods.
Make/buy a brace that mounts to the brake MC/firewall that goes to the shock tower.
Put the biggest brakes on that the rules allow. Run cooling ducts to them and use race pads/shoes and expensive DOT 4 fluid.
Switch to braided brake lines.
If you use regular roller rockers, just know that one day you'll upgrade to shaft rockers. Don't doubt me
Buy a trailer cause your car WILL break down at the track.
Get over having "pretty" paint. It's gonna get peppered all to hell.
You're not going to believe how fast you'll go through tires.
6pt or more cage and all the safety gear you can muster. Having your head pop off your neck or burning up is a terrible way to die.
Proper harness, 5-6pt camlocks are not that expensive.
A good seat that holds you in place and is properly attached to the rear main hoop.
Fire ext is a minimum, a system is better.
A coolshirt setup will make the day a lot more enjoyable.
You WILL have more fun and comradery than you can possibly imagine!