This lightweight nylon plate from Pilot is excellent for beginners. A 16 degree plate, the Eagle gives you stability without losing maneuverability.
The Plus version is more customisable and features adjustable pivots and a micro-adjustable lock nut on the kingpin. This plate is lightweight, exceptionally easy to use and has very little break in time for most skaters.
Note: Pilot plate sizes equal the distance between the axles, so a size 5.5 plate has a distance 5.5" axle to axle.