You dont have to grind anything. If I recall, you can create a pvp character that is level 20 in both primary and secondary class and start fighting. Sure there is better equipment and skills to find, but you arent a complete invalid and you didnt have any grind to get there.

GvG is a bit different from the normal PvP. It syill involves PvP but actually involves your Guild Hall. There are different 'games' that are played in both juts like WoW BG. There is a KIng of the Hill type, capture enemy priests, really a wide variety.

PvP was pretty fun and like was said above you can just make alvl 20 to play, although if you play PvE you can unloack better weps and skills for that lvl 20 char.

Yep, when you find the gold (maybe other colors as well) weps ect, if you break them down youll get a message saying you've 'unlocked' it or something. Then when you create your lvl 20 pvp guy you can pick and choose various wep combinations.

I think when it comes to that you have to get your main up to 20 and use him/her for the PvP.

I have to disagree a bit. When you've played your PvE Char a bit, he is at least the same, if not better than a designed PvP-Char. Its right, all skills, runes and weapon enhancements you found in PvE are available (without the need to buy them) for any PvP-Char you create, but there are some nice weapons out there you only find in PvE. Its a small difference but it exists.
For example, the typical shield for a warrior needs a tactics-skill of 12, but there are drops of similar shields needing less skill, so you can focus your points on other areas.

If you really dont want to do PvE, you can "buy" skills via reward points you get for winning games and for kills in PvP. But that takes longer.

A typical GvG-combat is an 8vs8 game (if i recall right it will be 8+8vs8+8 in Factions) on one of the guildhouse-isles. Each guild picks an isle when they buy a guildhouse, there are various styles with some slight tactical differences (quicksand, siege-engines and so on).

All isles have a flagstand in the middle and a fortress with your guildlord on each side. The goal is to kill the guildlord. If you own the flag, you get a morale boost every 2 minutes, giving you a +2% bonus to your hits and mana (to a max of 10%) and more important, refreshing your "reviving-signets", so you can resurrect members (that signet is fast, but one use only unless you get a morale boost).
If you dont get resurrected, there is an auto-resurrect every few minutes. Killing people is not that easy however. When you have competent priests with you (usually 2-3 of the 8 ppl) they can keep their ppl alive unless the enemy manages to focus fire.

I liked GvG a lot... i played relatively successful from begin on, with one of the premade chars (the Trap-Ranger), my role was to be the flag-runner and respectively to hinder the runner of the enemy from reaching the flagstand by planting traps around it and using my slow and disrupt skills. A ranger is a good beginner char, since the enemy focusses on the priests and other squishies first. I could run around relatively safe and learn without dying too often.

One of the nice things of GvG in GW is that there are no "servers", you dont have to rely on a propably limited or unbalanced "server-population". So the longest wait for a match was less than a minute (the typical duration is 15-30minutes).
And you usually only get enemies around your own rank and skill.
I remember one evening, our guild was rank 950 and after a winning streak of 9 games in a row we scored rank 150 and the guilds we had to fight then were clearly too strong for us. (That was short after ladder-reset, we later scored 700+)

The more professional PvPers have other modi, there are special arenas for the more advanced guilds, victories and kills there give you pvp-reward points (others than those mentioned above).
If you score enough points you get a rank which you can make visible via /rank -command. This shows an animal animation, the animations start with a deer...wolf, tiger... and so on.

Its an epeen-thing and you usually dont get invited into groups there unless you have rank 3+, others even require rank 6+ (hundreds of fights). Additional to the ranks, you score advantages for your region (europe, america, korea and soon japan) there. If you manage to win often enough in a row, your region wins the "favor of the gods", that means that all your players may do some quests otherwise unavailable and more important, you get access to the underworld, a more "raidy" PvE-Area (max Team is still 8)

Best "friend got pwned so hard he never played again" post EVAR!!!