Adding to the guide already written regarding finding cute suits for the young professional woman, keep in mind that while you may want to buy every trendy suit you see, you also need to buy those suits that are going to stay in style for years.  Always have the basics in your closet, such as black, navy, tan and gray.  Those suits can be paired with endless options, such as satin blouses, striped tanks, or sweaters - each time creating a different look and color combination.  Additionally, there are times when you will need a more conservative suit, such as a funeral or a formal occasion.

Trendy suits are certainly fun, but unless you have endless money, you'll need to strike a balance between trendy and conservative.

Also, go through your closet at the beginning and end of each season and purge what you don't want.  Suits are easily resold on ebay if they are in excellent condition - or donate them to your local charity.  Don't keep suits that don't fit anymore or that you are just sick of  - and definitely those that are out of style!  I help various women at my law firm go through their closets and get rid of the junk.  You not only then have room for more, but you are better able to see what you have, and don't dread looking in your closet every morning because things are disorganized or shoved in random spots.  I have my closet organized by non-work shirts, anywhere shirts, dress blouses/shirts, blazers, pants and then suits.  My shirt sections are then in the order of the rainbow.  It's easier to find what you need that way. 

For example, say you decide to wear your black suit with either red or pink, to go with that new purse you just bought.  So you check your blouse section and decide you aren't in the mood for something with a collar.  So you go to your "anywhere shirts" section and head directly to the red or pink section and pull out that sweater tank you had in mind.  There you go.  Done. You didn't have to dig through your pants, blazers or suits, all the while wondering if that red tank was at the dry cleaners, in the laundry room or buried  behind some pants.

Speaking of dry cleaners, I've had great success with dryell for certain materials of suits, especially if the item is just wrinkled and you hate to iron (such as cotton or linen), versus stained or soiled.  Suits may not need to be dry cleaned each time you wear them and you needn't have the skirt cleaned if you only dropped food on the jacket.  Make sure to point out stains when you stop at the cleaners.  The spots will get missed if you don't, resulting in a re-clean.

I hope this has been helpful to you - please read my other guide about various brands of suits that have styles for younger women who don't want to be boring.

Thank you!

PS:  For those in Canada, I recommend H&M, Tristan and Mexx for fun career suits and shirts.