K.C.
Do it when you have the time and energy -- you never know how things are going to go! My first pregnancy was trouble-free -- until my water broke unexpectedly at 33 weeks. I was admitted to the hospital and stayed there until my son was born a week later. (I even missed the baby shower, which was scheduled for two days after I was admitted to the hospital. My husband went to it -- they stuck a pillow under his shirt, pinned on the corsage, and let him open all the gifts! He set up the video camera and taped the whole thing so I could watch it later and brought me a nice "doggy bag" of treats from it.)
With my second, I ended up being basically put on bedrest from 28-36 weeks and never knew from one checkup to the next whether I would come home or be sent to the hospital again, so every meal I cooked, I made double and froze half of it so my family would have something to eat if I did end up being admitted. I wasn't supposed to even push a vacuum cleaner around, let alone do any deep cleaning, but I had a great friend who came and cleaned my house thoroughly a few weeks before my daughter put in her appearance.
As far as "advice" on adding Baby Number 2, I can tell you that the one thing I made sure I did every day for weeks before mine arrived, was to take my son on my lap and tell him that a new baby was coming and would take a lot of Mommy and Daddy's time, but that didn't mean that we loved him any less. I told him that love grew when there were more people and that just meant there was more to go around. My mom also sent my son a little boy doll after our daughter was born so that he would have a baby to take care of while I was taking care of the our baby. (Nearly five years later, he still loves that doll.)
This is an exciting time! Best wishes to you!