CONGRATULATIONS!!!
I would suggest, if you aren't against it, finding out what sex it is as early as possible. Then you can have the outfits ready, decorate the baby area, etc. which will give you an easy feeling of accomplishment early-on. Get the word out to friends and family about the sex, as well, and hopefully they will help you stock up on the basic baby needs you may have run out of since last baby. (lotions, new cloth diapers or disposable, etc.)
Mine weren't that close together, 2 yrs 8 days apart. I got the older one potty trained before baby was born. *yahooo!!!!*