Congratulations on getting to this important step in your transition. It is an exciting and anxiety producing event to have surgical breast augmentation.
You don't elaborate on the type of implant, placement, or insertion method you and your surgeon have selected. The least painful and fastest recovery are implants placed over the pec muscles. However, there are studies that show an 11% increase in capsular contracture of the implant when placed over the muscle as compared to under the muscle. The vast majority of BA surgeons do submuscular placement these days for that reason. On the other hand, the submuscular implants will cause your breasts to move up when you flex your pec muscles, and will not flatten to the side of your chest when lying on your back the way natural breasts and round implants placed over the muscle do.
What type of silicone implant will you have implanted? There are round silicone gels and highly cohesive (shaped) silicone implants. These highly cohesive implants (also called gummy bears) have a longer life expectancy than the gels, and will not leak if the implant breaks down. They can give you a more natural looking breast, especially if you have very little natural breast tissue and minimal body fat.
Depending on the type of implant and placement, you will be required to wear a compression bra for 2 weeks post-op to provide for proper healing. The first week is brutal especially with the submuscular implantation. You really shouldn't plan on doing anything with your arms, including driving. Over the muscle recovery is usually much faster because the pec muscles are not cut away from the chest wall nor stretched out to accommodate the implant.
PM me if you want more information.