You can purchase all the information even a trained mechanic could possibly need on ALLDATA. This is a great database for all cars sold in the US. 🙂

remember - when you’re working on cars use your brain. even when following what seems like simple instructions. You can easily mess things up and cause a lot of damage.

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Personally when I was starting out (Fixing my first car - a Renault Meganè) I relayed a lot Haynes, and good old fashioned guessing. 

https://www.alldata.com/diy/en

I bought a Hayes service manual for my 2007 Ford Escape at Autozone in Houston, TX. It cost ~$26.00 with tax. The book contains good information, but the pictures are small and in black-'n-white. I used the guide to replace the automatic window regulators in the driver's door and a rear passenger door. FYI: I also relied on two Youtube videos. (Thanks, Scotty!) I recommend you get one and read it carefully. I have no background in vehicle repair, but I was able to do it myself and saved a ton of money.

I always bought the factory shop manual for vehicles I owned.  It was quite expensive, but I knew I was getting the correct information.  The Haynes and other manuals are sometimes a little generic in their information.  I never went wrong with the factory shop manual.

Is this what you are looking for?

kiopman.com/kia_optima_tf_2011_year_service_manual-742.html

Paid services like All Data are also available