the field guide in the kit is agood idea.
afer that try the edibility test. you take just a little bit of the plant/fruit and taste it ad swallow it and wait 6 hrs. if no ill effects, probably safe to eat. if there is some kind of bad reaction, no go. also seems like there was one where you put the sample at your elbow joint and squeezes it and then looked for skin reaction., but I DO NOT KNOW FOR SURE ABOU THAT ONE. also we need to remember that just because it tastes bad doesn;t mean it is not edible. and some things you will need to cook in order to make them edible.