Business wear

The first thing to dressing well is having the "eye" for how a good fit is. The best way to do this is by looking at more images of well dressed individuals. Many people don't realize that they're wearing clothes that does not fit properly because that's what they've been exposed to all their lives.

Bad fit:
Good fit:
As you can see on the bad fit, although the shirt fits on the shoulders, there's a lot of excess cloth at the body as well as the arms, causing a lot of bunch.

Keep your dress shirts classic for business, have them mostly in white or colors that are a few shades from white. Stay away from dark colors like navy and black.

For your dress pants, have them in gray/navy/black and you won't go wrong.

For shoes, dark brown/chestnut goes with everything except a pair of black pants. And black goes well with all the pant colors mentioned above. Choose oxfords or brogues and go for slimmer fronts like these: