Part 1: Understanding the Basics

Welcome to my simple, step-by-step Pokemon breeding guide. There are many ways to reach breeding goals and some people will do it differently but I can guarantee that if you need any help breeding quality Pokemon with strong IVs then this might just be the guide you're looking for.

*Note - This guide will be focused on breeding Pokemon in Black 2 and White 2. This method can be used for Gen IV but in some scenario's the outcome's may be harder or not as accurate*

Part 1 - Understanding the Basics
Before we can even consider the first in-game step to take to become a breeding expert it is important to understand why Natures and IVs are so valuable to us. Every caught or hatched Pokemon will have one of 25 different natures and a spread of permanent IVs. To keep this simple and so there is no head scratching before we begin I will first talk about natures and then IVs.

Part 1(A): Natures
The first point to remember is that natures effect one or two Pokemon stats out of a possible 5. These five are its Attack, Defense, Special Attack, Special Defense and Speed. Each nature will increase one stat by 10% of the Pokemon's base stat but it will also decrease one stat by 10% of the Pokemon's base stat. The reason for their being 25 natures is that there are 25 different combinations of increasing and decreasing these stats. The list below gives details of these natures:

Adamant - Attack is increased and Special Attack is decreased
Bashful
Bold - Defense is increased and Attack is decreased
Brave - Attack is increased and Speed is decreased
Calm - Special Defense is increased and Attack is decreased
Careful - Special Defence is increased and Special Attack is decreased
Docile
Gentle - Special Defence is increased and Defence is decreased
Hardy
Hasty - Speed is increased and Defense is decreased
Impish - Defence is increased and Special Attack is decreased
Jolly - Speed is increased and Special Attack is decreased
Lax - Defense is increased and Special Defense is decreased
Lonely - Attack is increased and Defense is decreased
Mild - Special Attack is increased and Defense is decreased.
Modest - Special Attack is increased and Attack is decreased
Naive - Speed is increased and Special Defence is decreased
Naughty - Attack is increased and Special Defence is decreased
Quiet - Special Attack is increased and Speed is decreased
Quirky
Rash - Special Attack is increased and Special Defense is decreased
Relaxed - Defense is increased and Speed is decreased
Sassy - Special Defence is increased and Speed is decreased
Serious -
Timid - Speed is incresed and Attack is decreased

As shown, 5 natures will have no effect as they increase one stat but also decrease that stat too. Therefore these natures are useless to us and I would recommend disregarding these when focusing on breeding. The other 20 natures indicate which stat they increase and which they decrease by 10%. Different natures are beneficial to different kinds of Pokemon. For example, A Gyarados would benefit from an Adamant or a Jolly Nature as these play to Gyarados' strengths of good Attack and Speed. On the other hand Jolteon would benefit from a Timid nature as its base Stats favor Speed and Special attack so it doesn't matter about the decrease in Attack. It is very handy to know your Pokemon as a breeder but don't worry, there's no need to revise all the Pokemon's stats. Instead I would suggest going to www.smogon.com and searching for the Pokemon you are looking for in the search bar. This will bring up a page for that Pokemon showing its base stats and from that you can decide which natures would benefit which Pokemon.

Hopefully you're all with me so far and can see why we must take natures into consideration when breeding strong pokemon.

Part 1(B): Pokemon IVs
Now on to the tricky part! When you catch a Pokemon or hatch a Pokemon it will be given a set of individual values or IVs for short. These IVs are what many refer to as a Pokemon's genetics. Once the Pokemon is born there is no way to change them without cheating. As legitimate breeders, that is not the route we will go down.

It is important to note that each of the six Pokemon stats (HP, Attack, Defense, Special Attack, Special Defense and Speed) will each be given an IV but also note that IVs are not limitless. A Pokemon will not be born with 100 IVs in attack and 900 IVs in Speed. Instead these values spread from 0-31. What is even more problematic is that we can't check a Pokemon's exact IVs just by looking at the summary screen. So without making this too complicated, I will let you know of the best in-game way to check for IVs.

1 - Check the summary screen of your Pokemon. Under the Nature and caught/hatched location it will give a little phrase and this briefly indicates the Pokemon's highest IV (as shown in the examples below). I'm not going to go over this in massive depths because as breeders we are only interested in getting those 31 IV's in our selected stats. Therefore any other phrase then the ones here will not help us. Here are the phrases that may indicate a 31 IV in which Stat:

HP - Often doses off
Attack - Likes to thrash about
Defense - Capable of taking hits
Special Attack - Mischeavious
Special Defense - Somewhat vein
Speed - Alert to sounds

Those phrases are only rough guesses. What they actually indicate is that the IV in that stat either ends in a 1 or a 6. So as an example:
My newly hatched Eevee has the phrase "Alert to sounds" and what I can take from this is that
a) Its highest IV is in its Speed stat; and
b) that IV either ends in a 1 or a 6

2 - Luckily its not a guessing game because of the very useful boy in Gear station in Black and White 2. The boy in Gear Station can actually tell you which stats your Pokemon has 31 IVs in. He offers to examine your Pokemon and then lists the Pokemon's stat with the highest IV and follows it up with another phrase (hooray for phrases!). The phrase we are looking for is "It can't be better in that regard". 

With both those methods in mind, this is how we use them. In this example I will use two Eevee's:
Eevee A has the IV's 7/12/17/3/25/31 (HP/Atk/Def/Sp.A/Sp.D/Speed)
Eevee B has the IV's 12/25/2/6/10/26

As i have highlighted, both the speed IV's end in a 1 or a 6 and therefore both Eevee's would have the phrase on the summary page "Alert to sounds". The only difference is that when we take them to the boy in Gear station, only Eevee A will receive the phrase "It can't be better in that regard". So Eevee A would be our winner and Eevee B would be boxed or released.

Important - Please note that the initial phrases which indicate a potential 31 IVs in a stat cannot cover more than one stat. Therefore, when you take the Eevee with the phrase "Alert to sounds" to the boy in gear station he may say its Attack and Speed "Can't be better in that regard". So your IV spread could look something like this:

Eevee A - 9/31/24/8/20/31 

There we have it for this part. Hopefully your heads aren't hurting too much and I've given you a greater understanding of the importance of Natures and IV's. Each Pokemon benefits greatly from a beneficial natures and 31 IVs in its stats. I will go into greater depth about how to breed for IVs later on in the guide but for now it is just to outline why they are important. What I will look at next are the basic tools in order to help your breeding be more efficient.