Several great comments, WB6BYU and N0ZYL are right on the money.
The doppler is one more tool. I have used mine to find jammers. As others have said, you need a stronger signal. But once you do, it is almost a simple job to drive right up to the source.
That said, with our local hunts, if anyone shows up for the hunt with a doppler, they are in a different category. They may be first, or the lowest mileage, but we encourage everyone to learn to use a beam, lean multipath, learn your equipment, much like what the others have said.
I've done over 200 hunts, and I have seen brand new folks show up and beat me. It's usually because they adhere to the guidelines that I taught them at a club meeting, and me? I start guessing and ignoring my equipment. Silly me.
Please, try a doppler if you want. Use a Byonics microtransmitter or the Pircon controller and send a family member out. Take your time to learn, switch over to a beam and attenuator. But have fun.