EN: ENergy. This measures on a scale of  1-4 how much fighting a certain character can dish out before becoming exhausted.
AP: Attack Power. This shows the physical strength on a scale of  1-6 of a character on how much each hit moves the power balance in favor of the attacker's team.
DP: Duration when Powered up (flared). This indicates on a scale of  1-5 how long a character can remain flared with energy before becoming exhausted.
PF: Power when Flared. Whenever you flare, your attack power will usually increase. On a scale of  1-7, this shows how powerful your fighter is when flared up.
ME: MEteo power. This scale of 1-4 depicts the amount of life force that is stripped away from an opponent after each meteo attack, or how powerful the meteo attack is.
OA: OverAll. This scale, 1-26, is simply the sum of each attribute. The higher the fighters attributes, the higher his/her OA is.

Goku
EN: 2 / 4
AP: 2 / 6
DP: 3 / 5
PF: 5 / 7
ME: 4 / 4
OA: 16 / 26

Translated, this basically states that Goku has an energy level of  2/4, meaning out of ALL the other characters, he has about half the energy of the character with the most energy. His strength level is about one-third that of the strongest fighter, his meteo is capable of beating a fighter in the fewest hits possible, etc. Generally, the higher numerator, the better the attribute. If an attribute reads 1/# that means he/she is almost lacking in that area (very weak or little energy) and if the #'s match (4/4, 7/7, etc.) that means that he/she has about the maximum of any character (maximum attack power, energy, etc.). This applies to all areas except OA, which runs on a scale of 1-26 even though the character with the highest overall (Vegetto) has an OA of 24. This is because the MAX. OA is the sum of the maximum amounts of each attribute.

So, here are the scales.

Remember that these values are estimates. While characters here may perform differently from others with equal attributes, it will not be by very much. These values are approximations, but are still quite accurate.