Start by figuring out why you want to homeschool.
Then determine whether you're suited for it, temperamentally, educationally (and by that I don't mean "do you have a degree in k-8 education, which is of extremely limited value to a homeschooling family, but are you you well enough educated to know your own strengths and weaknesses, as well as your child's, and how to overcome or compensate for them), emotionally, physically.
Then search your state's homeschooling laws, and determine if you can work within that framework. States vary widely-- some require little to nothing, some require incorporation as a private school, some have a number of other hoops to jump through.
Find other homeschoolers in your area. You can function well enough as the only homeschooler in a crowd of schooled kids, but it will take a different effort than if you have access to a number of friends at co-op, play group, or other HS-friendly venues. Likewise, if all the other homeschoolers in your area are crunchy earthy granola folks with kids named Cypress and Willow, and you're a Pentecostal Christian who thinks the Duggars are scary liberals (or vice versa), you'll probably get irritated by being painted with that stereotyped brush on a regular basis. But at any rate, check out what's out there.
Also, consider your audience. Don't ask people who are dead set against public school (be they teachers, in-laws, or casual subway acquaintances) about homeschooling. It wastes your time, and just provokes the idiots into being...well, idiotic.
Figure out your budget, and whether you can accomplish what you want on that amount of money. If you think Broadway plays are a must, and your budget is a couple hundred dollars a year...well, good luck with that. OTOH, you don't need thousand-dollar curriculum sets to homeschool, either.
Check out a lot of websites. HSLDA can be of use, but I wouldn't use them as a primary source (sorry, Becky, but I still think half of them wear tinfoil hats on a regular basis). Personally, I like Jon's Homeschool Resource better:
http://www.midnightbeach.com/hs/ I think they're far more balanced.
Anyway, if you still want to homeschool after that...welcome to the community!