Raloc, that's not been my experience. With the exception of Night Elves, I've done the beginning quests for humans, dwarves, taurens and undead without needing to group. The Night Elf barrow downs was the only area that I needed to group in to survive and succeed in the quests. I haven't played a warrior, yet, however, so maybe it's different for them than druids, paladins, warlocks, priests, mages and rogues. I also primarily do quest objectives rather than grinding (which I find boring).
Finding a good guild does make things a lot easier, however. Enduring Nobility, for example, has a mage tailor that loves nothing more than to provide full sets of silk bags (or better if he's got better on hand) to sub-level 5 guildies. The guild chat channel is also a nice information source. Just don't pull stunts like asking questions on the guild channel and then ask again on the general channel hoping for a different answer. We're really not lying to you.
As for keeping at the same level as other people in the guild, I guess it helps if you can maintain pace with a group that you get together with to do more difficult elite quests and instances. If other guilds are like EN, though, then a number of people will have multiple characters at different levels. In my case, Garos (druid) is lvl 52, Errand (paladin) is lvl 33, Takkor (warlock) is 16, Tipher (rogue) is 13, and Sundiver (shaman--hopefully going into the shadow guild once that's off the ground) is 16. Depending on what's going on, Garos may go with Venatrix (48 hunter) or Errand may accompany Etayn (18 druid alt for Venatrix/Kotik2) to the Deadmines. Etayn is also planning on accompanying Tipher and Takkor a couple different times through the Deadmines.
The trick for us is that we're mostly a low player count guild (as EN World members are scattered across servers and some are playing their horde characters exclusively or primarily) that has a larger number of characters. So whatever works best for our own enjoyment and/or ours and other guildmates' needs is what we do at any given time.
I guess it comes down to most of the game being soloable, but I enjoy the instances that require grouping; and with the guild set up and a few friends on the side, I can usually find appropriate groups for the instances. But a lot of my recent time has been at most duoing in Un'goro and the Burning Steppes. Still, I need to get a good run through Maraudon and the Sunken Temple. Those'll require groups.
