Mine are almost exactly two years apart. DD was too small to understand a baby was coming or even what that meant, so I really hadn't been able to prepare her much. But when she first met her baby brother, she was excited and took it in stride, as if she'd been expecting him. So many she did understand my little baby talks, after all!
The first couple of months were a bit crazy. It didn't help that it was winter, which made it harder to keep DD entertained. I tried to have lots of activities ready for her when I needed to nurse or be with the baby, but she'd usually just want to be in my lap. She understood she'd need to wait, although we had a few meltdowns about it. But overall, she was really good. I found that if I could get her to 'help', even in a small way like handing me a diaper, or gently stroking the baby's head when I nursed, then she felt included and happy. And sometimes she'd grab her stuffed elephant, lift up her shirt and "give milkies" to it while I fed the baby!
I was also very lucky, because my MIL lives just minutes away, and would often take DD for a morning or afternoon, to give me a break. It was much easier to shower or eat or get something done with only one baby around. But it also gave DD a chance to have some special time for herself, with people who love her. I don't know if that's an option for you, but if you have friends or family nearby who can help out with the older child, it can be a big help for you.
When people come to visit you and the new baby, make sure you have some little things on hand -- stickers, even library books -- to give to the older child so that they aren't left out if the baby gets gifts.
Now that DS is 8 months, they are having so much fun together. They play together, and they just light up when they see each other. It's wonderful. Things are so much easier now, too.
So I don't know if this advice has helped. Just remember, it's just like with baby #1 -- the first little while is an adjustment, but then it gets so much better!