From the standpoint of your weapon: Weapon Damage is king. Above all else, you want the highest possible amount of raw damage and DPS possible. Beyond that, you'll want to take a look at this formula to understand the value of other stats.
In short: at low levels, nothing is going to beat raw +Damage on any slot where you can get it (Rings, Neck, Offhand). As you increase in level, you'll eventually reach a point of inflection where the multiplicative scaling gained from adding +Dex is more valuable than the straight + Damage. This point of inflection will vary with other stats, and particularly with the base DPS of your weapon - your best bet is to simply keep an eye on the +Damage portion of the tooltip when comparing items.
As for stats like Crit and Attack Speed, the same basic rules apply. In general, .1 attack speed is worth 10 Dex, but this ignores the defensive benefits of Dexterity, and since attack speed bonuses are provided as percentage multipliers, you'll need to do some math. You'll need to run similar calculations with +Crit and +Crit Damage, but in general, unless you use skills or passives that rely on Crit, you can assume those stats are less valuable than the others.
Really, all of this comes back to one key point: Trust the Damage Stat on your Character Sheet. So long as you're doing the basics right (using a level appropriate, high DPS weapon), it isn't going to steer you far wrong. Beyond that, Dexterity is King, and everything else depends entirely on the magnitude of the stat that you get. An item with +Crit might be better than an item with +Attack Speed, based purely on how much of it is there.
Doing act 4 hell and farm gear is a good idea. If you can manage you can also try act 1 inferno but there you are more likely to lose your nephalem valor buff because you just have to switch around skill/runes to get past some rare/champion packs.
Act 4 hell can be done without spec changing with a versatile build and so you can keep your 5 stacks of nephalem valor up until you reach diablo which results in 2-3 rares (never had fewer rares) and 5-6 magic items and with some luck you'll find a great upgrade.
Also you wont die as much and with 5 stacks of the buff you find a lot more gold which allows you to go shopping in the AH.
Grouping up with more people at the level cap (you only get the buff at maximum level) could also help since 4 people get 2-3 rares and chances are that you get something for another class and vice versa - just make sure no one changes their skills/runes so they have 5 stacks at diablo.
Best Answer
Equipment selection is dependent upon personal preference and intended usage. The monk's primary attack attribute is Dexterity.
Relevant information can be found in this question, but essentially each stat has a use outside of damage calculation:
Elemental attack stats are useful if you can discern enemy elemental affinity.
Other stats to be concerned about are Money Find and Rare Find which are useful for farming cash or rare equips/components respectively.
Attack rate increases your DPS, but more importantly it decreases the amount of time between attacks which is important for attacks with effects like stunning the enemy for example.
Health for each kill or health from orbs increases will serve to keep you healthy.
XP bonuses from kills will help you level faster.
Spirit regen is useful if you use your abilities a lot.
Movement speed is extremely useful for attacking and exploring and running away.
Straight damage or armor increases are very straightforward to understand and can be compared mostly straight across against primary attack stat and Strength for the most part.
Subjective opinion to follow:
Personally, I don't worry about it too much. I try to boost magic or money find as much as possible in order to find better base stat equipment and/or materials. As far as other stats, my personal preference is to boost Dex because it boosts both attack and evasion. I try to raise my attack whenever possible because if you kill the enemies before they hit you, your defense wasn't really helping. I also like to keep some movement speed boost on because it is extremely useful.