Here is my list for items that were helpful from weeks 3-10. Look in the January postings for my list for birth-2 weeks. Baikal seemed to develop more motor skills and a longer attention span after week 6, so I separated the lists because I noticed a dramatic difference in her ability to tolerate and enjoy new items. Swaddling was no longer of interest to her either after week 6, so she needed more clothing on when sleeping and being carried around. Most of these items you will only use for a short period of time, so buy used when you can!
Weeks 3-6
Bouncy seat-there are a lot out there, but I really like the bouncy seat by carter's called cradle and soothe. Pros: it can be carried and can recline fully to make for easier bottle feeding.
Bibs-get the 10 pack terry cloth ones. Put them on when feeding baby from bottle or breast to catch spillage. Also great to put on when baby is excessively drooling or spitting up.
Mylecon drops-help relieve stomach gas when you just can't get a burp out of baby.
Onesies-after belly button falls off, these are what baby wears. It is nice to have some long sleeved ones for colder days.
Pacifiers-there is a lot of debate about them, and Baikal didn't take one for about a month. There are way too many to choose from, so I don't have much advice on any particular brand. They have been useful though.
Sheet savers-once baby moves into the crib and out of swaddling, these really help reduce the times you have to wash the sheets!
Front carrier- I have used my baby bjorn almost every day since given the OK by my doctor. I opted for the "active bjorn" because it had longer straps for Matt and had better back support. It has been great.
Snap and go stroller- I wasn't interested in the full travel systems, so I got this frame stroller. I have been very happy with it. Pros- since it works with all infant car seats, I have been able to use it with other babies and it will be easier to resell. Also, it is a good bit cheaper than buying a whole travel system.
Weeks 7-10
Activity mat-any will do.
Swing- I really like the nature's touch baby papasan swing. Pros: it can fully recline and is made for an infant.
Socks, Pants and Coat-put these on baby when it gets cold. Any will do.
Sleeping sac or gown-I have used both. Once Baikal started to get out of her swaddle at night, I switched over to these. The sleeping sacs are easier, but more expensive. Gowns are hard to get on, but provide a quick access for night diaper changing. Tip: I cut the elastic off the bottom of the gowns to make them easier to put on. Once they are not needed as gowns, cut them into t-shirts. The footed sleepers can also be great. Especially for taking baby around in the car seat! However, I find that they make for more difficult night changing because of all of the snaps. It has been important to me to make night changing as quick as possible, so that baby and I can get back to snoozing!