Driving by car to Golden is the easiest way to get here, and this is the way I arrived. From Downtown Denver it is a short 20 to 25 minute drive and between 15 and 20 miles to get to the Golden Downtown area.
If you going to Golden from Downtown Denver get onto Interstate 25 Northbound and then after a few miles take the exit for Interstate 70 Westbound - the sign will not say anything about Golden but probably something like "Grand Junction," which is a lot further away than where you are going.
The route I take as I live in South Denver or if you are coming from anywhere South of Denver is to take the 6th Ave Westbound exit which is actually a 6 lane freeway through Lakewood and on to Golden.
RTD-Denver has great bus service in and around Golden. If you ever get really lost, look for a 16, 17, or 125 bus and that will eventually bring you back to downtown Golden. 16 goes up and down Colfax, and is a great way to get to downtown Denver or the Mall. Golden really isn't that big, so unless you're going outside of the town you don't need RTD.