As non premium it looks like this:
lvl 1-32 Questing
32-36 = a bit of grind 37-43= questing
44-47= grind and then youre grind free till like lvl 61-62 (free ppl start to grind a lot from then on)
Premium account: 1-45 = questing 46 = grind 47-63/67(depends on if you got a good XP scroll or if theres an XP event going on).
How you can see as premium theres only late highlevel grind BUT from some good sources I know that the so called "S2" patch or also called "RA" will be released somewhere this month and gives loads of new quests up to lvl 78 (yes level cap will be raised) so I cant really tell =) All I know is that this game is really fun even with that grinding areas you WILL have in this game!
But compared to other free mmos the grind is really kept low and the raids and pvp are fun even if they are not 100% well balanced ( again, after this S2/RA patch this might change a LOT)
You might want to check this blog for information about the RA patch
I hope I was able to help!