There are some excellent suggestions already posted - I have to agree Whistles are great for contemporary work wear. Just wanted to add that you might also want to try & Other Stories,
http://www.stories.com/ They have some fab shoes and accessories. Banana Republic also have some good quality basics.
Looking at blogs is a great idea as sometimes it is not so much the individual items but how you put them together that can make the difference - colour/print combinations, shoes and accessories are key. I would suggest pulling together some images from magazines, websites and lookbooks, as it really does help to have a picture in mind. Just focus on a few key outfits, as trying to get a whole new wardrobe can be a bit overwhelming. Invest as much as you can in basic items, such as, black trousers, shoes, jacket/raincoat and handbag as these don't need to be changed every season.
Hope that helps.