40” - 41”= 120-180 pound person
42” - 43”= 150-220 pound person
44” - 45”= 180+ pound person
In general, if your weight is covered by multiple lengths, the shorter length will be more maneuverable and the longer length will allow you to stay on plane at slower speeds. If the board will be used by multiple riders of different sizes you should go with a board based on the largest rider’s weight. Shorter boards are better for skateboard flip-type tricks. Larger boards are more forgiving for wakeboard-type tricks.
Second, determine the material you would like for the board. Board options are compression molded (composite) or wood. Compression gives more of a wakeboard feel, while wood is more like a skateboard.
Third, determine which board shape you would like. Flat boards are the standard for beginners. They are very basic and often times less than $100. Conversely, concave boards provide more pop and control, as well as enhanced ability to do skateboard-style tricks.
Finally, decide what type of top you want. A foam top board is soft enough that the rider could ride shoeless if they were so inclined. Grip tape tops provide a skateboard-like feel and hold better to the rider (who will probably be wearing shoes). Grip tape is like sandpaper and can cause abrasions if you scrape against it.