HELP! - Need to update my wardrobe :D

[SLAM<3 Always]

So I work in a very large company and depending on the office the clothes range from tshirt, jeans and flip-flops to extremely conservative. My office is somewhere in between. I tend to fall into that rut of dress pants and a sweater everyday which is getting really boring. Also, keep in mind that it's cold where I'm from during the winter. Any ideas how to update the wardrobe or good sites to look at for trends or good buys?

Thanks!