THE SUIT CHEAT SHEET!

A suit's gotta fit right or it isn't worth wearing.
In order to make sure that it does fit right, get it tailored.
You'll never go wrong wearing at two-button suit with a fairly narrow lapel. It's both classic and completely modern.
Flat-front, relatively trim pants; very little break at the ankle.
You should be able to easily cup your hands beneath the hem\edge of the jacket; if you can't, it's too long.
Show some cuff. It's the mark of a (well-dressed) gentleman.
Dress with the season - cotton suits in summer; tweeds, flannels, and corduroys in winter.
If you're going to wear a patterned suit, keep the patterns subtle. You want a smart suit, not a kooky one.
If you ever can afford to get a bespoke suit, get one made. It's worth every penny.