Congratulations! Guinea pigs are adorable animals!
I have 3 piggies who are turning 3 this year and 2 that are turning 2. Over the years I have done a lot of reading and learning and love them to bits.
My girl Ella, is also a long haired pig. Long haired pigs require daily brushing and regular trimming. I tend to cut Ella's hair so it stays up off the ground - that way it avoids it dragging and knotting. She is also my only piggie that requires a wash. She has a full body wash about every 3 months and I give her a bottom wash (the area that tends to get the messiest) as is needed.
I would actually advise you try to keep him inside. They don't do well with cold conditions (in comparison to buns which can cope a bit better because they develop that thicker coat) and likewise hot conditions (can get heat stroke, I have seen it happy to someone else's pig and it is not fun). It is also easier to monitor them. I believe they are even more fragile than rabbits (my personal opinion) and can fall ill easily and quickly. Anyway, just my opinion and if you do choose to keep him inside I can show you some pictures of my set up. Otherwise I believe that the same size requirements apply - I tend to follow the table on this page as a general guide;
http://www.guineapigcages.com/
For pellets, I feed Oxbows Cavy Cuisine. It is up to you which one you choose but as pellets in general are the least important in a guinea pigs diet, they only need around 1/8th of a cup per pig per day. Veggies are one of THE most essential things in a piggies diet. This is because they can not make their own vitamin c and so are prone to scurvy. I would avoid adding the vitamin c drops to their water - they tend to make the water taste funny and deter the piggies from drinking it. The vitamin c also disintegrates quickly in the sunlight. So - the best way to get them the vitamin c they need is through a wide range of vegetables. I tend to base these on a leafy salad (all lettuces are ok except for ice berg lettuce which causes diarrheao) and then add things like capsicum (REALLY good for vitamin c), carrots, cucumber, cherry tomatoes. Other veggies like bok choy, parsley, mint, basil, celery etc are also rotated through to provide viarety. They also need plentiful amounts of hay (in unlimited quantities) - this is to keep their teeth nice and trim.
Guinea pigs are MESSY! :lol: You will learn that very very quickly. They poop LOTS and wherever and whenever they want!! :lol: They do however tend to poop the most where they eat. As a result I have a "kitchen area" which consists of a pan (with sides) about 75cmx36cm. In this area I use kitty litter made 100% from recycled paper products. I have a hayrack with hay, pellet bowl and water bottle in this area. I spot clean it daily, removing the soiled litter and replacing it with fresh.
In the main area of their cage I use fleece and towels. It works really well! The fleece wicks their urine through to the absorbent layer underneath (towels). It lasts a week between cleans, and I just sweep up the poops daily.
You can definitely introduce him to a male. All the myths you hear about males fighting etc is wrong. They do tend to require more space as they tend to be more dominate, and they also tend to require multiples of everything (multiple drink bottles, food bowls, hidey holes etc) but they can get along perfectly fine. I have read of cases where there are 10+ boys living happily together. Just introduce them in a nuetral area, and then once you can tell whether or not they will get along ok (give them a few hours to work out who's boss) they can go into a freshly cleaned cage. It is important that the cage is cleaned beforehand so as to remove all previous scents.
Hopefully that helps some! And congrats again on your little boy!