Maple is, unfortuantely, a bit of a waste. You can spend the dough on it, but it wil ferment away to WTF in a porter.
Pumpkin is a puzzle. You can certainly get fermentable sugars out of it. If you want "pumpkin flavor" the general concensus is to use a 1/4to 1/2 tsp off allspice of pumpkin pie spice in a five gallon batch. Some brewers report "pumpkiny flavor" by using sweet potatoes instead of, or with som, pumpkin.
Lots and lots of recipes for pumpkin in the database. Several sections. Having played with it I strongly encourage 3gal test batches and keep your expectations low. Do you really want five gallons of liquid pumpkin pie cluttering up your closet?