Hayne's is alright...but, if you really want to learn about rx7 is to get a hold of Shop Manual. It's lot more than Hayne's...but, it would be an investment that you won't regret.
All in actuality, you'll need to drain all the fluids(brake, gear oil, coolant engine oil) and then replace filters (fuel, air) and ck and replace old vac hoses/fuel lines to gain optimal performance ready to be tuned
Make sure to replenish fluids that you drained...hehe
I use Royal Purple for lubricants.