Alright, so I decided to make myself an efficient character for once (e.g. always getting +5 on the attributes of my choice etc.), so I checked up on the exact leveling system - I had a rough idea, but wanted to get more precise infos. Sooo I checked out the UESP Page Oblivion: Efficient Leveling (http://www.uesp.net/wiki/Oblivion:Efficient_Leveling).

It keeps talking about how one should make sure to get +5 in all three attributes that are desired. BUT then I read this:

(UESP Quote):
The only way your character's level advances is by gaining ten levels (in any combination) of the character's major skills. On the 10th advance, you reach the next level. Unlike many other role-playing games, when you kill a monster no exp is gained. Similarly, when you level a minor skill no exp is gained.

0 skill increases, then you will get one point for picking that attribute
1-4 skill increases, then you will get two points for that attribute
5-7 skill increases, then you get three points for that attribute
8-9 skill increases, then you get four points
10+ skill increases, then you get five points for your selected attribute
(Quote End)

So, let me recap
1. To level up, I need to get a total of 10 skill increases in my major skills.
2. To get +5 for a certain attribute, I need to raise the related skills by 10 points in total (eg. for +5 Endurance I can raise Heavy Armor by 3, Armorer by 4 and Block by 3)
3. Considering points 1) and 2), how do I get +5 in more than one attribute? If I need 10 skill ups in a related major skill for ONE attribute, I would need 30 skill ups in related major skills for +5/+5/+5..BUT I level up after getting 10 major skill increases. So, as I understand it, it is impossible to get +5/+5/+5 (although thats what it tells me to do on the UESP page)....correct?

Im really confused :/

Increases in Minor Skills also contribute to your Attribute bonuses. So if you want +5 to three Attributes you'll need to raise your Minor Skills 20 times and your Major Skills 10 times. For example, if Blade is a Major Skill and Heavy Amor and Alchemy are Minor skills and you wanted +5 to Strength, Endurance, and Intelligence you could do the following:

Raise Alchemy 10 times = +5 to Intelligence
Raise Heavy Armor 10 times = +5 to Endurance
Raise Blade 10 times = +5 to Strength

Keep in mind that once you raise your 10th Major Skill your Attribute bonuses are set for that level, so be sure to increase your Minor Skills first.

Damn..that makes efficient leveling very tedious, and boring..is there no way to get +5+/5+% without "training" minor skills?

No, if you want +5 to three attributes (or even two attributes) you'll need to work on your Minor Skills too. To be honest though, efficient leveling is not needed and as you mentioned, can be tedious and boring.

Getting all +5's generally does require a lot of tedium, especially since you can't purchase more than 5 levels of training per character level.

I agree that it isn't necessary to do by-the-book efficient leveling in order to enjoy the game. However, a poorly constructed class will cause you to level up way too fast with too-small attribute increases. So, all of the leveled enemies in the game will become proportionally more powerful than your character as you gain levels. Unfortunately all of the stock classes in the game are poorly constructed.

What I always do is ensure that my character has at least some of its main skills as minor skills. E.g. my "pure mage" character has Conjuration and Mysticism as majors, but Alchemy as a minor. I use Alchemy all the time, so I always get several additional skill increases toward Intelligence every time I level.

The other very important thing is to never have major skills that you use constantly. Athletics, Acrobatics, and Sneak are the best examples of this; you use them all the time, and they increase fast enough through normal use that there is no point in making them major skills. If you do make them major skills, you'll likely level up much faster than you want.