I am currently homeschooling my 7-yr-old ADD son and homeschooled my daughter through 9th grade, when she asked to go to "real" school, so we put her in private school, and then the last 3 years she did a combination of private school (for subjects I'm not good at; literature and history) and homeschool.
I decided to homeschool my daughter when I saw what kindergarten did to my best friend's little girl. She went from a respectful, obedient little girl to a disrespectful, sassy kid (which she still is). My daughter was past the cut-off for starting (she was born in October) and although I could have put her in school early, her best friends weren't going in early, and I thought I would just wait, so she could start school with her best friends. But in that year that we waited, she learned, just in the course of playing and talking and living, all the stuff they teach in kindergarten, and by the time it came to put her in, I realized she had nothing to learn academically in kindergarten, and all she would be learning was the snotty, bad behavior of other kids (like my best friend's daughter had done) and I didn't want to lose my well-behaved little girl! So we started homeschooling and never looked back. I would never do anything differentnly! Besides, God give your child for YOU to raise. Why would you turn them over for 7 hours per day to people you don't know who may or may not have the same value system you have? (Incidentally, my daughter graduated high school at 17, took the GED test and scored so high that they gave her a silver embossed GED certificate. She had no trouble at all in college. We handled socialization by outside activities, ballet, choir, art class, Sunday school...she certainly never suffered in that regard...and in fact, when she learned all the "politics" in 9th grade, was glad i had spared her all that garbage all along.)
I don't know how you get started in the middle, as we started at the beginning. I used "Writing Road to Reading" which is phonics based (and trust me, whatever reading program you use, be sure it is phonics based, not "whole language"). It teaches the sounds of letters and letter groups, and the children first learn to write language, and I have never actually "taught" reading. It just happens with this program. My daughter and son were not ready to read at 6 (although both my dh and I read at 4). But both knew all the letters and the sounds they made, and both of them, overnight it seemed, just began reading. With my son, he has had severe vision problems, and we have had big breaks in his education for various reasons, but during those breaks, he just kept on learning.
You DO have to work hard in the first few years making sure you drill the addition/subtraction, multiplication/division facts, because it needs to be right there, and the only way to make it that way is to drill, drill...but there are lots of fun ways to practice (and games, like Monopoly Jr, reinforce the addition and subtraction, and they don't realize they are learning).
My son is right now at the tail end of first grade in math, second grade in science and history (which you don't even have to do in 2nd grade, if you don't want to--we just do it because he loves it) and third grade in reading. We spend 2 to 3 hours per day homeschooling.
The main thing is to get the basics in math down really good (Abeka is a wonderful math program) and encourage them to read read read. The elementary years are when children's mind are like sponges, and these are the best years to get lots of facts into their heads (the presidents, the states, scripture memorization, memorize poems, whatever they are interested in).
Kids naturally want to learn and are curious. Follow their interests and their learning styles, and they will not fight. If they do fight, there is a reason. When my son was first starting to read, he could hold his attention on a book for about 15 minutes, and when we got to harder books (and the print got smaller) he got down to 5, then he would fidget, change the subject, cry, kick, anything but read. We did not understand it until we realized how severe his vision problem was. He was able to hyperfocus for about 5 minutes, and then he could not force his eyes to see anymore, and what he could read 5 minutes ago, he could not read now...and that was the confusing part. We thought it was ADD or stubbornness. But when we got his glasses right, he just took off. He reads everything now. He has been reading for a year and is at 3rd grade level.
We go to the library a lot and get simple books on things he is interested, trains, bugs, etc.
Curricula: There is no end to the amount of curricula available for homeschoolers. We have had great success with Abeka. if you get the lesson plans, it gives you everything you are supposed to do every day.
Where do you work? We have done school in varioius places over the years. My daughter is distracted by everything that goes on, so we finally had to set aside a room for her to work in. Now we don't have extra space, so have a special shelf for books in the dining room and just work at the dining table. But that might be too high for a small child (my 7 tr old is almost 5 feet tall) for writing, so you might want to get a lower table/desk for her to work at if she is small.
We have always worked in the mornings, and we usually start with a fun thing, like Bible or Science and then hit the hardest, like math or reading. I think it depends on both you and your child. If your child focuses best in the morning, do it in the morning, if she is better able to sit still in the afternoon, do it in the afternoon. Or do part in the morning and part in the afternoon. There is no rule tha says you have to do it all at once. In fact, with my daughter, we broke it up into an hour in the mid morning, then an hour in the afternoon for first and second grade. You can usually amuse your younger ones with something for short periods like that.
Greg Harris has written a good book called "The Christian Homeschool" that talks about a lot of these issues. Socialization happens, if you talk to your kids, interact with them respectfully, and just expose them to other people, which unless you live in a monastery, is going to happen...you see people at the store, at the park, anywhere you go you interact with people, and your kids interact with people. There are countless extracurricular activities you will likely involve your child in, sports, dance, playing with friends...
We have a homeschool group that has about 50 kids in it now, and we do field trips as a group twice per month and that is fun. You might be able to find a homeschool group with people of similar interests as you in your area. (wow this got long...hope it helps).