What I mean by lightweight is that they don't require anything like OBSE or OBMM (I tried that out and wasted many hours trying to get my game to work).
As said already; you will REALLY want either (or both) OBMM or Wyre Bash for any modded game.
For load order, which will quickly become important for game stability.
As well as for installing any mod, even "lightweight" ones, in a fashion by which they can also easily be removed properly.
And both handle archive validation. Which you don't have to understand beyond the fact that some things, even simple ones simply will not work (properly or at all) without it.
OBSE is a very powerful tool, as it's name implies it extends the script functions far beyond those of Oblivion's original functionality. This allows for a lot of cool stuff, and some of the best stuff too! It is a simple install and forget application as well. All it requires is that you then run the game through it. The best two ways to do this, rather than creating your own link are:
1. Through Wrye Bash (that again!) or,
2. http://www.tesnexus.com/downloads/file.php?id=27672
With either all you need (once they are installed and set up) is to find and check the checkbox that says you are using OBSE, and the game will be launched through OBSE for you every time from then on.
And then you won't be limited to non-OBSE mods.
Neither OBMM or OBSE should stop your game from working, at all.
I'll take any mod you think is good, I don't care what category of mod it is (Quest, UI changes, etc.)
Thanks in advance! (FYI I only have the UOP installed in terms of mods)
As said; get the UOP supplemental patch (it is the continuation of the original, and is very well done by someone well known for getting it right.) As well as any unofficial patches for any DLCs you have.
Beyond that the world is your oyster, what do you want out of the game?
Want it to look prettier? More detailed?
Wanting more that the original (vanilla) quests?
More of a challenge? An easier ride?
Dissatisfaction with certain aspects?...
There are plenty of threads etc. on suggested mods, as well as plenty to look through on TESNexus etc. Just look around and have fun seeing what you might be interested in.