I'll make you a believer if 'ya let me Ski.
As far as the 305 goes....
It is Minelab's entry level machine, and is actually really more than most people (that have never owned an Xterra) might think. Compared to something like a 705, it makes you work, which is good because you really learn how to detect w/o all the auto features. It also makes you appreciate it when you get a machine that has the auto features.
Seriously, with 7.5kHz and 18.75kHz capability and the 9 available coils that you can set it up with, you should be able to find one or two that will optimize your hunting experience.
As ZR2guy posted, read Randy's book...it's priceless and free at the same time.
Watch videos on YouTube.
MinelabDetecting has one that is a good place to start.
Go swing that thing! Make it make noise at you and flash numbers on the screen.
Between the book and advice available here, we can help you sort it out in no time.