The process is pretty straightforward, but you need a little bit of equipment and clean buckets or milk jugs to collect the sap.
Then strain the sap with a mesh strainer before boiling it down to syrup. It takes a lot of sap to make a little syrup, but it's delicious. The ratio is: roughly 40 gallons of sap boil down to just one gallon of syrup.
Here's a link with step-by-step instructions, maple syrup.