I'm rebuilding my wardrobe slowly. Rather than give you a list of things to buy, I'll give you some thoughts and tips that I've learned over time:
1. Don't buy excessive amounts of things you wear rarely. If you only wear a suit once a year to weddings, don't go out and spend $3000 on suits.
2. Don't buy things just because they are on sale. Buy quality over quantity. That said, there is a level of diminishing return. IMO, a $30-$40 shirt is often much nicer than a $20 shirt, but a $100 shirt is hardly different than a $50 shirt.
3. Buy simple, unbranded items. If it has a logo on it, you probably shouldn't be buying it with rare exceptions.
4. In general, buy lighter shades of colors for dress shirts. I can't stand the look of a bright red shirt or dark blue / black shirt underneath a jacket. For dress shirts, buy mostly a lot of variations of blue.
5. Buy more solids. Use textures to separate them ( twill vs oxford vs herringbone ). If you buy stripes, keep them simple and subtle. A university or bengal stripe works well.
6. Spend more than you want to on shoes. This will seem outrageous at first, but they last and can be sold later for good resale value if you don't like them. No square toes, as mentioned. Allen edmonds provides the best bang for the buck.
7. Learn to layer with a lot of basics. V-neck sweaters, cardigans, blazers.
8. Don't buy modern trendy stuff. For example, suit jackets that are insanely short.
Here are a few companies that I think make decent bang for the buck stuff that are pretty easily available.
Dress shirts - Nordstrom trim fit, TM Lewin, Charles Tyrhwitt, Modern Tailor
Suits - Hickey Freeman, Benjamin (ehaberdasher.com)
Casual shirts - J Crew, Lands End Canvas (cheap!), Uniqlo
Shoes - Allen Edmonds
Above all else, make sure things fit properly. Just read a few style blogs, and copy exact styles from people you like. Avoid the super trendy weirdos.
Here's a great thread from styleforum under the Men's clothing section with focus on casual wear:
http://www.styleforum.net/t/253842/w...c-casual-style
Ignore the weird trendy **** on the first few pages - there's some good stuff if you dig through there.