Here is a quick, cheap and easy way to think about. Go down to you favorite Lumber yard and buy a 8 foot long 2x4 that is good and straight. Drill a small hole approxinately 1 inch from one of the ends and insert a long screw or nail into the hole so it protrudes through the other side. Stick the Nail into the ground at the approximate center of your pool, and then all you have to do is put a carpenter's level on the 2x4 and spin the 2x4 like the hands of a clock around the "axis" and check level. You will see if there are gaps under the 2x4 and you will be able to see where you are high and low. Finally, in my area, the roughed in dirt pool area is covered with a layer of sand, and the 2x4 comes in real handy to "skreet" the sand flat, level and smooth.

The 8 foot 2x4 should give you a good 16 feet of "level" ground for yor 14 foot pool.

Hope this helps