I think the only method that makes sense to me is to install one mod at a time, and run Minecraft to see if there are any problems. But with the list of mods I have, well over 100 mods, that's gonna take quite some time to do - very tedious indeed. But if I just dump a ton of mods in and run Minecraft, the error list will be such a jumble I'll be lost.
Also, am I going to have to make a lot of changes to cofiguration files? How will I learn about what settings to change, just by trial and error and based on experience?
With a list that large, you might try breaking it into smaller chunks - like, say, groups of ten. If you've seen certain mods grouped in other packs, those would be good to add simultaneously. Add a group of ten. Check for errors. If errors, check the log files for obvious culprits, remove, and repeat.
As for configuration files, I've found those less intimidating than I expected in my own limited pack-creation. Pull them up in a simple text editor like Notepad and page through them.