Probably asked before but

I've read several tutorial type docs and right now I'm just trying grasp what they say. I start Construction Set and go to Data Files where it lists the three esms - MW, TR and BM. What next? One FAQ said double click on the MW esm so that it's marked and that CS will figure out the rest. Another says don't worry, that CS automatically includes MW but to double click either or both TR and BM if your mod needs them.

I've taken the precaution to create a separate game folder to use for playing around with the CS.

So, first, let's say I want to try making a mod from scratch. I want to make and add a book that can only be read after the PC has reached a certain skill level. From what I've seen, I may have to write a script (I'll get to that later but not now). Should I check all three esm files or just MW because I think a script will be needed?

Because an esp is of what's been changed by the modder, when should I start saving a mod in progress? Should I immediately 'save as' giving it a name and start from there or wait until I've actually added/changed something stuff and then make saves until I'm happy with what I did? I normally rename a file before I even start doing anything in it so as to reduce the chance to mess up the original source data. Some FAQs mention that unnecessary(?) saves in the CS may actually add junk and introduce errors (GMSTs?).

I read a FAQ by Calislahn about adding stuff from resource mods into the mod you're making. It seems clear enough for the case where I have started working on a mod (has a named esp) that I can include in from the "Data Files" screen but what about where I want to start making a mod from scratch and immediately include something from a resource mod as I'm working on my mod?

And once I finish what I'm doing, how do I find those things I changed so that I can make myself a zip file to install into a real game? I know I'm skipping a lot of other steps. I'm thinking that I'll probably look for a nice looking book to use, write what I want to put into it, attach a script (saving that for a different time if need be) to it, place it somewhere convenient for PC to get and then save the esp. At the moment, I don't know how that changes files in the game and what should therefore be included with the esp itself.

Has anyone ever written a best practices FAQ to keep files organized during the process or what are the gotchas to watch out for?

John