It depends greatly on the child to be honest. A lot of our children ( we have homeschooled ten to one degree or another) are self regulating in that they set their own curriculem to some degree, as we've found if they learn things in an order that makes sense to them, then they learn better and faster. There was however one child that was really too disorganised to do this, so we had to be more structured with him. Initially you need to sit down and chat to him and find out exactly what he does know and then identify any glaring gaps in his knowledge that will prevent him making progress and fill them. Then identify subjects he's naturally good at or interested in, and subjects he hates. Set out strategies for making the hated subjects more appealing to him and set him something really detailed to do with the subjects he shows aptitude for. This will give him a high sense of self esteem, as he's bound to succeed with the detailed project because he's deeply interested in it.Once he feels that he can do things well, he'll become more self -confident which will help with the hated subjects and you can begin to allow him to steer his own path a little more and ask him where he sensibly thinks his education needs to go next to attain his full potential. Above all, make things as interesting as possible with trips out, research via internet and TV, museum visits etc, anything that is stimulating. Kids love learning if it's pitched to them in the right way and I've never come across a home schooled child that doesn't flourish once they realise that it's not a free ride being at home.
If I can be of any further detailed help let me know and I'll do my very best to help you. I remember very well being unsure how to best approach it when we first withdrew our kids from school, but now it feels a very natural method of schooling and once you are into your stride with it, I'm sure he'll be fine.