Can anyone tell me how to use chalk paint?

its actually quite easy with impressive results. First sand the area with 220 sand paper. Fill in any nicks or scratches with wood filler. When dry sand again. Wipe with tack cloth and paint with chalk paint. Annie Salone makes a good one. After first coat dries it will look not so great but give it another coat or one more if coverage is not good after dry now sand with 300 sand paper and wipe down again with tack cloth. Now give it a good coat of wax from a can. I'm talking rubbing wax here. Buff with soft cloth and you have a professional finish

If you are doing a small project, you can even skip the sanding, just clean and paint. Then put a wipe on poly over it or the wax. I have done many projects with chalk paint and didn't really sand at all.

what are you painting?????

just paint - no sanding. You do need to either put polyurethane or wax over it.

Here's a link for more information http://www.thepurplepaintedlady.com/2013/10/using-chalk-paint-outside/