good news! you only need level 58 for outlands. For me there are SOOOO many quests in your bracket that what I do is go to a few different places to break up the monotony so its not so boring. Winterspring is great, as are both plaguelands. PLus the XP on quests have been raised you should blow through that last level and a half in no time.
IM not much for guides but here is a step by step one, just open the level 56 portion and do it til you hit 58 and outlands. DOnt worry if its not exact, just follow what you can, you may have done some quest or missed a few, no biggy, just follow on to 57 and even 58 if needed until you get your level:
http://www.wow-pro.com/leveling_guides/jame%2526%2523039%3Bs_alliance_leveling_guide_-_chapter_iii_%2850-60%29
Also, I know the bore of leveling and all, and I went straight to outlands at 58 on my first toon, but you will be gimping yourself due to all quests you would have if you waited til 60 to go to outlands as any undone quests in outlands, instead of xp its straight up gold, and you will probably want to gear yourself up, by epic mounts and so on and the quickest way to farm the money is having undone quests, even the lower 60s ones (very easy for a 70 to blow through) as you can get 10-12G sometimes up to 20-24G per little quest.