In many places in the northeast and midwest, maple syrup season signals the start of spring, and there's no replacement for real, natural maple syrup. After you have it, those high fructose laden "pancake syrups" that you see in the grocery store will never do.
Step 1: Find your trees
Start off by finding a tree. There are several types of maples, and although the sugar maple is the best because it has the highest sugar content, any maple tree will work. A maple tree should have leaves and seeds that look like this. There are also many websites that can help you identify a maple by the bark. (Thanks to www.massmaple.org for the pic). The tree needs to be a minimum of 12" in diameter, and if your tree is more than 20" in diameter it can take two taps.
Many other trees other than maples can be used. Pecan trees make a fabulous syrup, but I've heard of people using sweet gum, birch, box elder, among others. Each species will have it's own unique flavor.