Another vote for the Rebecca Abrams book. I only read it 3 or 4 months after DS2 was born, and wish I'd found it earlier. Two is definitely harder in some ways, but easier in others. When DS2 came along, I found that looking after him was a piece of piss - I found myself thinking, 'How on earth did I ever find this baby lark difficult the first time round?'. However, the difficult bit second time round (IME) is looking after the toddler (DS1 was 2.11 when DS2 was born). Even though I had sworn that I would cut him a lot of slack, I was totally unprepared for how I fell out of love with him (having been totally besotted until the baby was born), and it horrified me. Reading the Abrams book was a godsend, because it made me understand my own feelings and learn to deal with them. Before the birth, I'd been worried that I wouldn't love the baby as much as DS1, but it was almost the opposite experience - next to the baby, DS1 suddenly seemed huge, and awkward, and whingy, and difficult, and, most of all, deliberately naughty and challenging - in a way that a newborn can never be. And SO old - he seemed to age years in the couple of days I was in hospital. Before the birth I did pretty much everything for DS1, yet when I came home with the baby I suddenly found myself thinking, 'For god's sake, why can't you put your shoes on/brush your teeth/get dressed etc by yourself, you're nearly three?'. Poor thing didn't know what was going on. And these feelings happened even though DS1 was relatively angelic, and was never anything other than adoring towards his little brother.
So yes, it is tough. But the first time you hear your baby giggling at your toddler (mine's now 8 months, and does an awful lot of giggling), it's all worthwhile.
And there are other good things, too. I was far too obsessive and anal about DS1, constantly trying to control every aspect of his life. Now that the baby's here I can't do that any more because I don't have the time, and it's made a huge difference to him - he's really grown up and become more confident and less clingy.
In terms of actual advice - I would say, don't worry about the logistical, practical stuff, because it will fall into place (and in any case, it's pretty difficult to prepare for anyway). Focus on working at the relationship stuff. Prepare your DS for the baby as much as you can by reading books etc (Shirley Hughes is wonderful). Read the Abrams book, and then read it again after the baby's born. Is your DS in nursery at all? If he is, it's probably a good idea to keep him in for at least a couple of sessions a week once the baby arrives. And if you're planning to start him for the first time, make sure you leave LOTS of settling in time before the baby's born (I left about 10 weeks, and it wasn't really enough).
Above all, enjoy. It's hard, but you'll love it.