Like most of the Boss pedals, you can pretty much just plug this thing in and let it rip. All you have to do is plug in your guitar in the input and the amp to the output. I had no need to look at the manual as I just adjusted my tone by ear with the 3 knobs and had no troubles setting it up.
This produces a great heavy distortion sound. Its really thick and great for sustaining a power chord. The distortion can range from just a light overdrive to all out heavy metal. However, I am unable to get a real tube sounding overdrive with this. I have only used it with guitar, and it sounds great with my amp that has no built-in distortion.
I've had this pedal for about 5 years, it was my first pedal. I like this pedal for the specific heavier distortion in produces. I use it mostly for rhythm guitar but doesn't sound bad for lead. I also have a BK Butler overdrive pedal to satisfy that sort of overdriven sound. However, the reason this pedal is so popular is the price. Since it is so cheap, even the most beginner level guitar players should have it in their set up. While there are certainly a slew of better distortion pedals out there with more versatility, for the price this pedal cannot be beat.