If you join a guild, it's possible to help out the guild by investing in a crafting profession.
The faction as a whole is pretty big, no one element is going to be a huge help.

I personally haven't gone into guilds much yet. If I were you, I'd start here: http://forums.elderscrollsonline.com/categories/guild-headquarters

RP = Role Play

Many people that play this game will Role Play, in short it means that player will, for the better part, know a fair bit about TES history and lore, they will have a character that has a name that is lore friendly. They are the type of player that will smell flowers, make things, kill things, basically do everything that fits into their characters character if that makes sense. Many people here on ESO have been playing games from the Elder Scrolls for many years, so there is a lot of history and tradition to their play.

As for smithing, yes someone has to do it! and no doubt it would be useful in a guild. For people that RP, and it's for your own personal enjoyment, then crafting and balcksmiting may well be for you.

If it's for getting the best armour for your character, it's been said many times that loot drops will give you the better armour than crafting/blaksmithing will yield.

I hope that helps you. Happy RP'ing (even if you don't know you are doing it!)

That's great thanks! I've been an TES player for a long time now, but this is my first ever mmorpg so I'm kinda a noob when it comes to stuff like that... looks like I better join an RP guild then, rpg's are kinda my thing