You will want to start by reading my article on tongue diagnosis. This will show the various aspects we consider within the tongue and their meanings. In general, the tongue shows more acute (or what is happening now) within the body and is quite accurate. The pulse will show deeper, more chronic issues but is somewhat more subjective and, accordingly, somewhat less accurate. That said, you rarely rely on a single diagnostic procedure. When you use the tongue, pulse, appropriate questioning, etc. you will come to clear and accurate diagnosis in the majority of cases.
Your tongue shows some heat in the heart area (the red tip), some minor liver qi stagnation (the mild teethmarks on the sides), and the white coating is a little heavier in the stomach/spleen area which may indicate some kind of digestive issues of a deficiency nature. If you look through the article and understand some of the basics, however, you can watch the tongue overtime and find what issues are more prevalent and which ones come and go. With appropriate treatment the tongue will change as your condition(s) improve.