That's not to say that you can't work from home, because you can. But getting random jobs from the internet will be a recipe for disaster. They will be low-paying, if you ever get paid at all, and you'll have to dodge various scams.
Instead, make a list of what you did before DS, and then approach companies offering to do those things for them. That way, you'll get to work directly with reputable companies, you know you'll get paid a decent rate, and there will be plenty of work around. It's just being confident and determined enough to get started - which you'd need to do anyway, because internet jobs have high applicant and rejection levels too.
Also remember to declare any money you make, and to consider paying your own NI incase you need it in the future.
Oh, last points - What Wilson says is correct. You'll need to find time to communicate with people during the day, and sound focused and professional. So you will need either a good routine (I know some people who work very part time during their childrens' 2 hour nap) or some help with your son.
What Himalaya says. Also, how do you envisage doing your work while your son is there? When mine was tiny I couldn't have done what I do now, not without childcare anyway. Have you thought of childminding as a way to combine the two?
What did you do before you had your DS? What are your skills?
I would anyone advertising generic "freelance homeworking jobs" - there used to be (not sure if there still are) a lot of scams like this.
Looking for freelance work will depend on what industry/function you are looking in. Some organisations advertise consultancy work, some use agencies, some have a pool of associates they draw on for projects etc... But it depends what the work is.
I'm trying to find a job where I can work from home with flexible hours - my son's too young to leave alone but we're really struggling to live off my husband's income alone. I've tried a few google searches but I can't find anything useful so I thought maybe other SAHMs might have been in similar positions and be able to point me in the direction.