I’m new to woodworking and was wondering about the best way to cut dados in MDF. I’ve seen tutorials on cutting dados in real wood using chisels, but I don’t know if it applies to MDF as well because I’ve heard MDF is much more flaky/crumbly than actual wood. I have access to a circular saw, which I was told by a friend I could use to cut them iteratively, but that just sounds like a pain in the rear. I don’t have any planes, and the only electric tools I have are the circular saw and my power drill. Is there a good way to do this without having to purchase other tools?
MDF is worked with the same tools, but it will be characteristically flaky, as you say, and it will tend to dull edges faster. It's not clear what hand tools you have exactly, but I am guessing you have chisels? If have only chisels and circular saw (power drill isn't very useful here), here's what I would do with your setup:
lay out the dado. scribe the lines with a marking knife to assure a clean appearance.
rough in the joint using the circular saw. Stay ~ 1mm away from your layout lines, but use the depth control to sneak up on the exact depth.
finish the joint using chisels.
To add on to @aaron's answer. A router plane, dado plane or rabbet plane will work fine in mdf. I would score a deep line if your tool does not have a knicker when starting. I would also take small bites. You will end up sharpening more.