Heres just bits of useful information,
Finding a pig
Make sure you find a good source for your baby. Pet shops WILL NOT have babies young enough for the younger/older boar process. Please try all the rescues within traveling distance before looking for a breeder. Even if they have no babies they will be able to put you in contact with a GOOD breeder. Not just anyone.
What you will need when coming to bond your piggies ?
Neutral area.
A neutral area basically means a space that smells like neither of the guinea pigs. During a warm day, the garden in a nice sized run may be a good option or another indoor option could even be the bath tub with a towel laid down.
Bonding food.
Something like grass, or a bowl of veggies on a small plate that the two piggies can sit around eat together, a nice big pile of hay is never a bad idea either.
Towel.
If all does go wrong you should NEVER put your bare hands in to separate two piggies that are fighting. Throwing a towel over one of the piggies and then picking them up is the safest option to avoid injury to you or the pigs.
Hideys.
All hidey houses and areas used during bonding should have at least two exits to prevent any piggies becoming cornered or trapped inside them.
Another thing when bonding an adult with a baby is to try and make an area that only the baby can get into, so that it can escape the adult if it all gets too much for them.
Older boar with baby.
Boars are notoriously the more difficult of sex's to bond, due to male hormones running high and the fight for one to be the more dominant.
Getting 4 to 6 week old baby boar is thought to be the best chance you have of getting your piggies living in pairs. The success rate of introducing new pigs is higher with this method. The older of the two piggies are likely to take on the 'daddy' role as such.
When it comes to the bonding process, allow a small controlled area to be available with easy access for you to stop any scuffles that may occur, put them both in the caged area, in this area you should have at least two hiding places, one preferably that is only accessible by the baby, also a nice pile of hay or maybe a bowl of veggies or some grass to munch on, do not take your eyes of them for at least an hour. Things can change fast during the bonding process.
DO NOT: Bath a tiny baby boar to remove the scent. In theory this is a good idea but a little baby will not cope with the stress or water. Better to put dirty bedding into his coat. He will then smell of the big boar and this will completely confuse him for a bit.
Two adult boars.
Bonding two adult boars is a slightly harder task but not impossible. It is best done over a gradual period of time with alot of care.
Day 1
First take each guinea pig in turn and sit them on a blanket on your knee. Let the other guinea pig sniff the blanket after the first guinea pig has gone back in his cage.
Day 2
Sit both guinea pigs on your knee together. They should not fight in this situation, even if they do not eventually get on together.
Day 3
The next day take both pigs out of their cages and introduce them on neutral territory.
You may hear alot of squealing and loud noises, also its common to have alot of humping but this is all normal dominance behaviour. For more information on the dominance behaviour between guinea pigs go to the 'behaviour' page. As with bonding an adult and baby, the controlled area should have at least two hidey house areas with at least two exits to prevent any cornering, the same with the bonding food and hay pile also.
If the bonding process does not go well, a bonding bath is a good way to get the two adults to have similar scents.