Say, you have 12 Intelligence (+1 Modifier). You take the first level in Ranger; this gives you Ranger Base (6) + Int Modifier (1) points (total 7). And since it's your first level, take 4x this number (28). Next level in Ranger is 7 points. Then take a level in Barbarian, you get Barbarian Base (4) + Int Modifier (1) = 5 points.
Note that subsequent Intelligence increases don't retroactively give you skill points, nor do temporary Int increases (such as magic item "Headband of Intelligence" which gives you +2 bonus to Intelligence). Oh, and Humans get special +1 skill points per level. And again, if you have 8 Int, you get -1 to your skill points (level 1 Ranger with 8 Int would get (6 - 1) * 4 = 20 skill points).
If you only take 2 levels of Ranger, you basically just pick which bonus feat you want on level 2 from the various options (which include Power Attack in Dragon Magazine Extra Styles list).
It also requires 6 levels of Fighter to fully gain the benefits. Fighter doesn't get a lot of skills or interesting class features so this is kind of a downer.