The first step in becoming a Mommy is you have to find a Digimon couple that is already established. After you find the Digimon Family, you steal one of the eggs from the nest.
The first thing to do when you want to hatch your new Digimon is find an egg. You can't make any Digimon without finding an egg. So for the first step, locate an egg by doing one of the following:
A] Buying a DigiEgg from the Cash Shop/Item Mall with Account Points (AP)
This assures that you will get the Digimon that you are looking for if you happen to be searching for the Digimon in the Item Mall/Cash Shop.
B] Fight a monster and scan the Scannable DigiEgg that you find.
Note that this may be very hard to find one this way. It is a chance if you get one. The only assumption is to get a High Quality Scannable DigiEgg for that chance.
C]Fight a monster and obtain a Scannable DigiEgg that says it is a Digimon.
These eggs will glow a Orange/Gold color and have a digital looking aura.
D]Do a quest and obtain a Scannable DigiEgg or a DigiEgg that can be put into the Incubator.
Some quests actually give DigiEggs that you can just put into the incubator to get a Digimon.
Example below of a Scannable DigiEgg that can give Items, etc.
To scan the egg before putting it into the Incubator, you have to find an NPC that can Scan the Egg. NPCs that can do this are Miku.
After you steal the egg, you have to sit on the egg for a LONG time before you can actually hatch it. Be sure to get snacks, a small television, and something to do while you wait. It might take days, weeks, or even months!
With Step 1 finished, you can move to the second step. Make sure you find an Incubator in the towns around the game's world. Incubators can be found in locations [more locations to come]:
Example of finding the Incubator:
After you find the Incubator, you can click on the "Create Mercenary" and it will direct you to a screen much like [without the completed Incubation]:
To hatch the egg you will need to location some Data Chips. These data chips are required to hatch an egg, and can be either slightly difficult or fairly easy to get. You can get these chips by either:
A] Buying them from the Cash Shop under Digimon and click around until you find the Data Chips you need.
B] Finding eggs and Scanning them into Data Chips. This is the only way to get them in game. You should attack a lot of Digimon of one type in order to scan large amounts of Eggs in hopes you get alot of Data Chips.
You will need a fair amount of Data Chips if you plan to hatch alot of DigiEggs. To verify the amount you need, make sure you hover over the egg and look into the item's details to see the requirement.
After you start sitting on the egg, the Digimon Family that you stole the egg from will probably come to get you. You better make sure you hide in a spot that can't be easily located. Be sure to also mask your scent. Digimon are known to have good noses.
Once you complete Step 2, you can move on to Step 3. You should have put the egg into the slot in the Incubator and are ready to hit "Data Input". You should hit it 3-5 times before you get a message that should say something on the grounds of "Your egg is ready to be hatched!". You will see a few message appear before the final confirmation that you have completed the hatching process. These will just let you know if that round was successful.
Note that there is a chance you might fail and this may result in the egg being destroyed.
FINALLY! You noticed cracking noises from underneath you. You have hatched your egg. Now to see what is inside. With any luck, it is what you wanted. Be warned. The family might still be looking for you!
Once you complete step 3, you can finally progress to step 4. This is the last step. You can hit "Hatch" and finally name your Digimon [keeping the ToS in mind]. Make sure that you have enough slots in your Partner slots to put in your new Digimon. This is located below your character's Avatar picture in the upper left hand corner.
[Note: If you notice mistakes, let me know.]