My pointers:
1) As Warren Buffet says about which stock investments to buy, "cheap crap is still crap". If you get something cheap, but you never want to wear it, you just threw away money. Then again, spending lots of money isn't the answer either. Knowing what to buy is your goal.
2) Look at how other guys dress. This has helped me a lot. You'll hear things about peacocking, wearing a certain style of shirt, etc. But, seeing a guy model it around in whatever situation lets you quickly judge if it's what you want. Most guys aren't paying attention to fashion, so pick and choose. But, in a club scene, most guys wear jeans and a baggy shirt. The stuff may look new, but it just comes off as crap, because it does not flatter them. When you see a guy walking around with a look you want, note it. You can say similar things when you are in a coffee shop, etc.
3) Read. Learn what works. Look at the pictures.
4) Get the advice of a woman you trust. However, be sure you trust her. Lots of women are out to make you look "nice", not "attractive". This is a difficult one to pull off.
5) Just buy a couple things at a time. Do not go out to find an entirely new wardrobe. Try a couple of things, and develop your style.
6) Give away things you just don't wear/don't like. Without spending a dime, I immediately improved my dress the most by doing exactly this. The issue is, when you have crap hanging around, you feel you should wear it.
My best store is Macy's Mens.. I grab things on sale. I get shirts and pants for under $50. I've gotten nice shoes for around $50. All of it is on sale. But, my personal style is a masculine look. Am not going for "groomed", but I certainly don't want childish.
Sticking with basic fashion rules will get you more than spending money. For example, your clothes should fit. Baggy clothes just won't make you look more attractive, unless you want to hide a gut. Jeans and pants should be long enough to cover your socks, but not drag on the floor. Until you get some basic fashion going, I'd avoid spending lots of money on one or two particular outfits.