Hey MP-
Congratulations on the new job, that is very exciting!
As for where to buy suits and the such, I am a big fan of Banana Republic. Love Ann Taylor and Ann Taylor Loft, but their pants don't fit me right. At BR be sure to try on the various different cuts of pants. In dress pants I swear by the contoured fit (I am a definate hour glass figure with BIG hips and thighs and these aren't too tight there as many dress pants are) Also, in the stores they only cary the regular length and petite in some stores, but online they also carry short and long versions of almost all of their pants. And if you buy full price they will do the hemming of pants and jacket sleaves for free. Also, if you get the BR store card you get %15 off your first purchase (did this when I bought my first suit) and then you get $10 and $25 rewards cards for each $250 you spend in the store (I think that is right, they keep changing it, for the better). As you can see I am a big fan :-)
I used to love J.Crew, but they have gotten really expensive, don't have great sales, and I have actually had problems with the quality going down. Other places to try to seperates are the big department stores, Macy's especially as they always have great sales. I don't have luck with suits there so much since they are mostly sold as sets, and I am different sizes on the top and bottom (in fact I am a petite on top, but not on the bottom) so I am a fan of places that sell their suiting as seperates.
Good luck, and have fun shopping!