What to do when a recipe

Just got a recipe book called 200 clone beers. All the recipes have extract and all grain procedures. I plan on brewing the all grain most of the time.
In the all grain directions most of the brews say to mash at one temp for a certain amount of time then bring the temp up for another x number of minutes. Ive never done this type of mashing, was wondering would it be ok just to mash at the higher temp for the total amount of time.
Also they say to use less bittering hops in the all grain recipes. It will say something like use 20% less chinook. I got to say 20% less of a half ounce has got to be only a few pelletts.
What would your do?

What kind of mashing do you do?

Single temp infusion. Then continuous sparging

Are you familiar with the original flavors? I did a clone and it didn't come out like the original. It was more like a different beer I know and enjoy. It was listed as Edmund Fitzgerald. I think it came out more like Summit Great Northern Porter.

It only matters if you will know the difference or someone else will "call you on it".

If you just want to get it right. One way to bring up the temp is to draw off some of the mash wort and heat it up - then add it back in. I do this, usually because I'm not getting hot enough mash temps. I want as much grain conversion as possible.

The recipes don't tell you how much mash water, sparge water, and at what points?

You need a jeweler's scale for the hops. You might want to (gasp!) do things in metric which makes it oh-so-easy to do those calcs and measurements. 28 g to one ounce. 14 grams times .8 = 11.2 grams. Wow, that didn't hurt a bit!
(sorry for going over the top here)

If they are listing mash out temps you should be able to easily achieve that through the addition of boiling water, I think green bay rackers has a calculator for how much boiling water to add. If they are giving step mashing directions that might be a bit more difficult, though still achievable with the addition of boiling water as per calculator.
http://rackers.org/calcs.shtml/

I don't want to be a nay-sayer , but every recipe is based off a certain brewing system. What results I achieve won't necessarily happen for you. If I were you, I wouldn't try to brew what is in the book. I'd set a personal goal to achieve a certain beer style. Then I'd keep tweaking my recipe until I'm happy with the results.

Stepped mashing isnt hard to do, you just need to be methodical and (once again) understand your brewing system. Mash temps are easily calculated and certain styles require stepped mashes.