Really do your research. Others will tell you the same: Alchemy punishes the unprepared.
Have a clear idea of what you want to do, whether it's to craft items for yourself (up to and including backwings), the achievements, the challenge of it all. Plan out your Levels 1 through 10 (no seriously). Decide what you are going to make when, figure out what needs to be made first (quite a few formulas have prerequisite components that you can craft at lower levels, might as well get the maximum XP you can), and above all budget (especially if you're looking to make gold).
Remember first and foremost that Alchemy was meant as a goldsink. It is possible to fund yourself via Alchemy and even to make a profit, but you really have to keep an eye on the MP--what's selling at what price and if it is worth it to craft.