Alright, here's how hit works.
First, you have special attacks. To cap hit for special attacks so they never miss, you need 7.5% hit, or 2550 rating (1% hit = 340 rating at lvl 90). Once you hit that point, your special attacks will never miss. This includes Bloodthirst, Raging Blow, Wild Strike, Colossus Smash, etc.
Next there are auto attacks. Normally, capping hit for specials would also cap auto attacks, but since Fury is a dual-wielding spec, you have a 19% miss chance added onto this. This means you need 26.5% hit (9010 rating) to cap auto attacks. Both main hand and off hand auto attacks have the same miss chance.
It's not advisable, however, to cap hard cap hit since hit past 7.5% isn't very good for DPS. It's not terrible, but once you hit that point, you should just focus on crit (to a certain point, but don't worry about that right now).
The 15% number they're likely giving you is from needing 7.5% expertise (also 2550 rating) to soft cap expertise so you see no dodges (from behind bosses; you'll still see parries if you're attacking from the front for some reason on some fights). If you have 7.5% hit and 7.5% expertise, you won't see any misses or dodges (with specials) from behind. You'll still see auto-attack misses however, but again, that's fine.