Using BOSS to sort out your load order can handle a number of issues...
I have never heard of or even used BOSS where do you find it, does it have a website?
I've also found Windom Earle's Oblivion Crash Prevention System for OBSE to be IMMENSELY helpful for preventing crashes as well.
I have heard of this is it in the Elder Scrolls Wiki I think I found it there once.
Installing them right, having a good mod manager and load order, having a good computer, using the Script Extender Crash Prevention (If released), re-installing the game after all that didn't worked. (Oblivion Experience... But if it's more like Fallout 3 and New Vegas, Crashes will be less frequents with time and patches.)
So I should make sure to have all three of the first things you mentioned.
It really depends on the mods and what other mods you use. If you only use a handful chances are you won't really experience problems. I found that Fallout 3 and New vegas are infinitely more crash happy than oblivion (i blame a large portion on the patches). I was running something like a 100 mods on Oblivion and very rarely experienced crashes. The best thing to do really is try to avoid mods that are known to increase crashes. A word of caution be very careful when editing your ini file. I did a simple modification of extending the duration blood persists and as a result crashes skyrocketed. Another time i followed a tweak guide to improve some performance and the game actually didn't even run anymore.
I want small mods for houses and cloths maybe better bodies for certain outfits. Maybe later on something that could upgrade the textures and maybe something to add weapons.
Thanks you all trying to educate myself on the subject of mods for when I do get a capable PC to run them.