Allies, Allies, Allies.  KAW is a pointless game when you have zero allies.
So, what IS an ally?? An ally is another player that boosts your stats when you hire them.  This is the easiest description.  Every player has stats and is worth a certain amount so learning to find the best stats for your money is key.  Allies are CRUCIAL in growth and growing your kingdom.  Can you play without allies?  Probably, but it’s not reccomended because with allies you get more money faster.  So read the guide on allies so you can buy your own and pwn in this game.
So lets talk stats.

So see where it says Attack Bonus, Defense Bonus, Spy Attack Bonus, Spy Defense bonus?  Most people look at that and think that ALL those numbers add into yours.  That would be awesome if it did, but they don't.  Only 2% (TWO) factor in to your stats.  I know that 2% seems like a small number but add that in with other allies you will soon own AND the bigger YOU get the bigger your allies get which means bigger numbers.
Now lets discuss the plunder bonus.  You receive an amount of that number (on all allies) on top of what your own troops bring in until you are maxxed out (plunder capped-you have the correct ratio of allies and land so every time you hit you are getting the max amount you can from your stats).

PLUNDER CAPPING (in detail and how to do it)
This is best to do in a pwar, but you can find anyone to do this on really.  Wait till your troops are at full regen.  Hit (attack) someone.  Write down the number that says ALLIES BONUS.  Now go ally searching while your troops are regening back to FULL health.  Find yourself a great ally and purchase it.  When you are FULLY REGENED attack that SAME person you just attacked.  Now look at that ALLIES BONUS again.  If that number went up, even by ONE digit, you were not plunder capped.  So rinse and repeat until you get the SAME number BOTH times.  And remember, you have to wait till troops are FULLY REGENED before EVERY hit and you have to attack the SAME person.  And to do it in a timely manner.  If you wait a day in between hits it may not be accurate because your target may have upgraded something in that time frame.  Also, you have to WIN the battle to get that ALLIE BONUS number.  Here is what the VICTORY screen looks like:

Now EVERY TIME you purchase land and either build or upgrade, you need to plunder cap yourself.  EVERY TIME.  So don't forget because this could mean billions of dollars in the end.

Lots of people actually buy allies to make a profit.  This can be a controversial (not to mention risky) form of gathering money, but to each their own.  So the entire purpose of allies is to buy buy buy.  So if everyone in the game is buying, 9 times out of 10 your ally is getting bought FROM you.  Sometimes it is worth it to keep buying back the ally until the other person gives up and sometimes it is not worth it because some allies are over priced and VOLLEYING (To VOLLEY someone is to have two people keep buying the same person over and over) them is all that will be accomplished in the end.  So when an ally is hired from you (and yes, this will happen....a lot...) you get back what you paid PLUS 1.5%.  So the more that ally is worth, the more you get.  The reason this can be risky is because sometimes you can buy an ally thinking that person who owned them will buy them back and they don' if you are plunder capped and you bought that ally assuming you will make a wasted money.  Also the other end of it is that some people get way to protective of their allies and will lash out at you if you buy them over and over from them.  So if they threaten you the best thing to do is to ignore them and find a different ally.

So now that you have all that down (right?? If not...reread until you can say it in your sleep) lets talk about WHEN you buy your first ally.  Try and get a couple friends to volley you until you are worth 1bil.  You get LOADS of money this way and you can use that money to buy your first alley and upgrade your kingdom.  However, if you have not made friends yet, or are not in a clan, or read the rules on begging for volleys so you AREN'T GOING TO DO IT, then you can do it the long, harder way.  Questing, questing, questing.  Quest and save your money.  This can be tedious, and take forever.  But, you get lots of benefits from questing, like crystals and nobility points which you can use under Marketplace>Oracle to refill your troops and spies (BOTH) so that you can keep questing or save those precious crystals and nobility points for wars.  Your first ally should be an expensive ally because they will have the higher stats that you need to grow.  50-100 million is worth dropping on an ally with good stats.  Choose your ally carefully because YOU CANNOT SELL AN ALLY.  You buy an ally and you keep that ally until someone else buys them from you.  You technically CAN get rid of an ally by whats called DROPPING them, but you only get half your money back, and at this point you are trying to MAKE money...not lose money.

There is a formula for finding if an ally is a good one...but like all have to be able to do math. For every 1K (1000) TOTAL in stats is 10 million in hiring cost.  So if they have 15k in stats they are worth 150 million.  And I cannot stress enough how important it is to not just buy an ally but to buy a GOOD one.