I have recently taken on several vehicle repairs. For the past 15 years or so, I have been the “go to” guy when friends or family needed a diagnosis and/or repair. I am quite the back yard mechanic, as far as back yard mechanics go. (No interest in making a career out of it) the somewhat rural area I currently live in, has afforded me a fair amount of positive feedback from several successful auto repairs and the chatter seems to continue landing me some side work as a “mechanic.” My question here is this-does anybody know of a site which I may acquire the standard book hours for a specific repair on a specific vehicle and part replacement? I’m aware all, or most shops have access to this information. But is there a public site in which I can reference for this information? This way, I can price accordingly, and have a thorough estimate beforehand. Which will also be beneficial to any future customers. Thank you in advance, to anybody who can share this info with me. 
You have to subscribe to a service like Alldata for information like that. Repair Pal shows labor costs for common repairs, that might be sufficient for your needs.
Try searching automotive flat rate. It took me about 30 seconds for more guides than I can count.
Question re: flat rate: does it adjust geographically? I mean, a car where everything’s rusted together takes a lot longer for me, as a DIYer, to work on. I figure powers tools would only help so much: some bolts would still be resistant; sometimes bolts shear off, or other complications arise when you have to take stuff apart that’s “rust-welded” together.
Two words. Hot wrench (Oxy acetylene torch).
I’m going to throw a word of caution your way - if you are doing this as a part time business, instead of a ‘one at a time helping the cute girl down the street’ kind of thing, you might want to look into some liability insurance. What if a car you worked on gets into an accident or…? Also, to keep on the up and up, you should really start a business and file taxes, etc., but that’s another can of worms.
I strongly recommend a subscription to a repair database service such as the one Nevada referenced. Not only will you get repair standards, you’ll also get far more information on the repairs than you could possibly get out of repair manuals, and that’s critical if you’re going to be repairing other people’s cars.
If someone who is not employed as a mechanic offers to help as a favor opens a rate chart I am going to a real mechanic.
I no longer have a lawn service so if I use my riding mower to mow a neighbors yard while they are gone all I expect is that they say thanks and possibly fill the fuel tank.
A word about using search engines. I took my old Mac to their “Genius Bar” because it was freezing up and I could not figure it out.
The young man who was helping me said, " I have never come across this before and “Googled” the solution.
I was watching him and thinking “Why didn’t I do that”?
Answer:
2 key words: Genius & Bar.
Didn’t Edison say something like, “Genius is 1% inspiration and 99% perspiration” ?
CSA
“Invention, my dear friends, is 93% perspiration, 6% electricity, 4% evaporation, and 2% butterscotch ripple.”
- Willy Wonka
I will strongly advise that you purchase a bundle of repair orders seeing as how this may become a regular thing.
Make SURE any complaint is written down in detail so there is no confusion later on and that you and the customer are on the same page about exactly what is going to be done, what kind of guarantee is provided, and so on followed by the customer signing the RO.
Doing this regularly is going to (with 100% certainty) have you dealing with someone who is “one of those”. You need to make sure all of the bases are covered before even touching it.
At the dealer once we had a guy who signed a repair order THREE times and then denied ever signing it at all. He even went so far as to say that we “forged his signature” and that he “never authorized us to remove the VW manual transmission and disassemble it”.
OP if wanting to actually charge for “shade tree” mechanic work is delusional. So many legal pitfalls. Business license, federal/ state income tax, state sales tax…
I would just stick to working on your own car, family member’s car, girlfriend’s car, and that’s about it
Don’t overcomplicate your life and open a can of worms