In the case of Maryland, the state group web sites don't seem to be immediately helpful about supplying the legal requirements for homeschooling. HSLDA does have an overview and legal analysis, however:
http://www.hslda.org/laws/default.asp?State=MD
Maryland compulsory age is 5-16, with the minimum being extendable by at least a year upon obtaining a waiver from the assigned school, so you don't have to worry about the legal requirements quite yet. Of more import is what curriculum to use. I assume you've already done the prep work of reading to your daughter and pointing out letters and numbers? If so, the next step is phonics / kindergarten. If possible, you should attend a meeting of a local homeschool group and take a look at what curriculums and/or methods they're using:
http://www.home-school.com/groups/MD.html
If this doesn't work out, you can always start with a packaged curriculum:
http://www.home-school.com/mall/curriculum/phonics.html
http://www.home-school.com/mall/curriculum/general.html
After the first year or so, you'll have had more time to get comfortable and develop some preferences as to what constitutes a good curriculum and what doesn't.