1.Spec Overviews and Talent Selection
The monk in 5.4 is can be a tanky source of good damage or glass cannon burst depending on spec. Brewmasters make fine pug fc's, not good at coordinated play though as a solid group can pop them nonetheless. As a healer mistweaver just isn't there. The healing reductions and burst damage of 5.4 make them and their undependable heals hard to play with any pressure from the enemy team. It can be done, but it's very very hard. They have quite a lot of burst damage though, so mistweaver dps is on the rise.
Brewmaster
Brewmasters can be big and tanky or a massive damage threat depending on how they are built. As fc's they can get across the field very fast and take quite a bit of punishment, making them ideal for pugs. However, without heals they do suffer and aren't very self reliant in that regard. For a premade, a warrior takes less damage and has more health, but requires more help to get across the field and also is not that self reliant. As a damage class they can hit very hard, able to build a lot attack power and not be that glass cannon due to ox stance. They are also pretty much un-kiteable as you would expect a spec with multiple gap closers and a spammable ranged aoe slow would be.
Mistweaver
The mistweaver is a unique healer that is kind of suffering at the moment. You have zero ability to heal while on the move, and the rng of your chi generation will keep your big heals from happening when you need them. With even more healing reduction now, I find mistweaver as a healer almost intolerable. Literally anything with burst can kill you, and prepare to smash your face into your keyboard every time some bad geared rogue dunks you because you had to sit and channel soothing mist for your third chi and it just didn't come. As a dps though, mistweaver hits really hard because of the passive muscle memory. They run oom pretty fast doing this, but it's viable. Just build glass cannon and try to one shot people with blackout kick.
Windwalker
My personal favorite spec, the windwalker is a huge source of damage. The mobility is the best in the bracket except for maybe druids. A berserker buffed, well healed windwalker is more than a force to be reckoned with. They are not well adapted for fighting multiple enemies, but can wreck anyone in small engagements. Don't expect to one-shot anyone, but you're not exactly a fury warrior. Hasn't changed mush over the expansion either.
Races
The monk is open to all races added before the cataclysm, with the exception of pandaren. Race is really your preference, but some have better things than others.
Alliance
Human - The racial is crazy good and allows you to pick up a second trinket. The expertise bonus applies to both maces and swords, which is insane considering how rare expertise is at these low levels and that it applies to both maces and swords(take that, dwarves!).
Night Elf - Shadowmeld is a great pvp racial, especially for healers. You can use it to drop combat for mana regen or whatever, and if you're fast enough you can meld spells like fear, even instant casts. If you need to get some heals off under huge pressure from interrupts and such, you can meld and then start casting, which will cause the melee to have to re-target you, giving you time to heal unhindered. Elusiveness is fairly good, and makes horde players have to stack more hit and makes you even more annoying to casters.
Draenei - Gift of the Naaru is useful for fake-casting and is great for being interrupted. For the melee classes, it's beautiful for survival. If Touch of Karma and Fortifying brew are on cooldown and you're alone, all you can do is try to kill them before they kill you or run away. This is a nice third option. Hit capping isn't super hard, but can help a melee mistweaver since you're not really focused on it.
Dwarf - Stoneform is a minor defensive cooldown that isn't super good. It never really has been, but let me explain. It's a super nerfed version of your cleanse and Fortifying Brew. It's probably not going to save you, and using it on a bleed would just be stupid. The mace expertise is good, but human does the same thing with a better racial. I like dwarves, but not the best.
Gnome - Monks are very vulnerable to kiting, even with all of their mobility, so the racial is nice, but if you are after something like that just use the Tiger's Lust talent. It's an improved version with a quarter of the cooldown. Shortblade specialization is good, but most of the bis weapons are maces. The extra engineering can net you
Rose Colored Goggles, but if you're going that route I would just use
Spellpower Goggles Xtreme. The mana is okay, but mana is almost of no consequence unless going in for melee on your mistweaver.
Horde
Forsaken - The best in my opinion. Will of the Forsaken is great. Most of the hard cc in this bracket is fear, and it works on pandaren racial and sap too. Cannabalize can be good for extended base sieges and fights and can save you if you've narrowly escaped a fight on a windwalker or brewmaster and have a dot on you. Touch of the Grave does a lot of damage and healing and procs a lot. Undead also have the ultimate swag points.
Orc - A good race overall. They have a passive stun resist, which is a big part of cc in this bracket. Blood Fury can just destroy people, especially stacked with berserker buff. It's also good for mistweavers in melee and casting, but more so for melee. The expertise with axes is a bit wasted since there's no real bis axes, but the fist weapon could be good if you go dual wield the heirloom fists.
Blood Elf - A big thing about monks is they lack an interrupt at this level. Blood Elf supplies this one, which is huge. There's no cc reduction or second trinket like the first two, which have two good racials each. I also really don't like blood elves since they're way too overplayed and the majority of people I see playing them are just noobs on trial accounts who don't want to be an "ugly" race. At least you're not another prot paladin, and anyone who plays well and responsibly is a good player in my book.
Tauren - War Stomp is kind of like Arcane Torrent, but has a cast time and doesn't give energy or mana back on use. Cultivation is useful to those who, like me, hate leveling herbalism with a passion. The health is especially good for brewmasters and other fc's, but for the other specs as well. Just a note, I respect those players who play "ugly' things to show off their maturity(i.e. female trolls), but do you really want to stare at an unshapely cow-woman all day? My advice is to play a male for higher swag points.
Troll - This isn't a bad race, but the racials just aren't very good. Berserking isn't that useful since healers don't have any cast time heals(if you're hard casting enveloping mists on people, you're doing it wrong) unless you're going for very specific amounts of haste to hit breakpoints. If you're trying to get big burst on your ww or dps brewmaster I'd just go orc and pick up some free stun resist. Da Voodoo Shuffle is a bit useful, but if you're that concerned with getting kited just using Tiger's Lust should be all you need.
Other
Pandaren - A decent race. The double food buff allows for such feats as 20 agility or intellect well fed buffs and since cooking is something you should actually have, the +15 skill is good. Quaking Palm is a really cool little racial, and even though it breaks on damage, if you use it at the end of a heal they might die before they can get another heal off, or you can, if solo, wait it out and hit them with a full fists of fury or something. I personally hate this race with a passion and I don't understand the new noob fascination with this race. They look so stupid and every time one kills me I want to punch a hole in my monitor. Once again if you're a good player and choose to embarrass yourself, I'm okay with that.