Definitely get a manual, then read it from cover to cover. This will give you most of what you need to know for jetting (In the adjustments or fuel section). Then do a search on this forum for advice specific to your bike.
My general advice,
a)never be to hasty, allow jetting settings to bed it before looking at plug readings, spooge etc..
b) make sure all other stuff in tip top, no leaks, good fuel, right oil/fuel mix ratio, no air leaks etc...
c) make small adjustments, never big ones unless you can be definite that the result is what you want, (EG going from a stock jet which is usually way rich from the factory to one closer in the ballpark) if you make too large an adjustment, and end up too lean you can do major engine damage.