Do yourself a HUGE favor, go to Radio Shack spend $15-20 tops and get a handheld microscope. If you just use it to look at the miracle you have grown and a first look at the trichomes, it is worth every penny! But where it pays for itself, is in the quality of your harvest and your ability to decide how you want the high to be experienced. Once you go through a harvest or two you will figure out exactly how you like that strain.
Lots of explanations on the board on how and what to look for when using a scope, if you run a search you'll find a lot on it. Basic gist is, you look at the top of the mushroom shaped trichomes; they start off clear this is not 'ripe' yet, when they cloud up they are starting to 'get ripe' and you are in a position to start to harvest when more than 50% of these have gone cloudy. You will notice that a couple of these will have turned red/purplish color; if you harvest now, you will have a high that is more on the 'heady' side and it may give characteristics similar to a 'sativa high' energetic more functional, ect this can help complement a sativa you are growing. When they are starting to get a majority of them (50%+) this reddish color (looks like they are bleeding) it will give more of a body high and produce effect more expected of an indica, couchlock, pain relief, relaxed feeling.
IMO with my first harvest it helped out a bunch and was a lot of fun to just sit with the plants for a little bit and see how it affects things.