It allows me to cut dovetails much better than I could just by hand. This handy little guide clamps on to the board and guides the angle of my saw as I cut my tails (something my sloppy sawing technique was really messing up). The big magnet keeps the saw stuck to the guide.
Then I can flip it over and cut the pins by carefully sawing in the waste area.
Also the woodworking guilds I belong to REALLY help. The two that I belong to are online (The WoodWisperer and the HandTool School). Then there are all those blogs to keep up with. So much fun and so much help.