Show DC1 where the nappies/wipes etc are stored and encourage him/her to bring these to you each time they need a nappy change (saves you doing it, and they can also do this for baby once it's born, makes them feel involved). Getting DC1 toilet-trained before the birth is a good idea if you have the energy for it.
I bought DD1 a dolly with a bath and dolly nappy etc, so when I was dressing DD2, DD1 dressed her dolly. She loved this.
I bathed both together, just filled the tub, DD1 sat, and DD2 had a quick dunk.
I used to BF DD2 on the sofa, with one arm around DD1 at the same time (and CBeebies on the telly, or book in her lap), so DD1 thought of it as her special time too although it didn't stop her trying to kill DD2.
Woke up before them at 6.30am each day (ugh), got myself showered and dressed, then got DD2 up at 7am, BF, dressed etc, and then DD1 up around 7.30/8am, and could pretty much ignore DD2 whilst helping DD1 get ready.
This meant we were usually out of the house by 9ish so I could get to playgroups, to see friends etc. I tried to get DD1 out everyday or we'd all go nuts indoors.
I remember staying awake at night panicking about how I would manage, but, wierdly, I found it easier with 2. They occupy each other, and keep you entertained. My DDs are now aged 2.5 and 4, they love each other and play together lots. DC3 is due in the summer.
You'll be fine :)