The experience system is pretty invisible -- there's just a popup over enemies that give xp, but since the xp radius is around you, all the creeps you're looking at are going to be giving you xp, so as far as you can tell you just get xp for everything. Add to that the shared xp bar (so you're constantly gaining xp for no apparent reason as other people do things) and the fact that the Team Liquid guide doesn't mention how xp works in MOBAs at all (just a blind spot for them, I assume) and you're going to get a lot of people who have no idea how laning works.
Blizzard should really give us some tool to see our xp radius -- something to hover over and get an overlay or something. That would help teach newbies and be useful to everybody else.
