For prophecies: Bolts of Cloth are a basic material for you ele's armour, with a secondary material like iron, dust, granite, scales depending on what armour line you want. Also you can get your belt pouch in pre sear for just 5 skale fins or 7 worn belts.
For factions: its a little different silk, linen, damask and cloth, iron, dust, granite, scales are more likely.
use your post sear ranger to get lots of cloth faster then just give your ele the cloth when she comes over.
in case you missed it there are 2 armor crafters in Ascalon city which have 2 different AL armor (15 and 30 for ele) each crafter has only 1 of them so get the AL 30 which can take you to (and beyond) Lions Arch
Look up the armors on Guildwiki to see what they need for materials and start collecting them. In Prophecies I plan to buy armor in Ascalon and upgrade it with collector armor in the jungle and desert for free then buy the final set in Droknar's Forge.
Plan on getting a head piece for each element (air, fire, earth, water) so you can make any build you desire. Note that the collector "hats" from the desert or south Shiverpeaks are equivalent to those crafted at the Forge so you can save some cash and materials by using them.
In reality, since I planned to play a variety of professions I just collected stacks of each material so I'd have it when needed. That expanded to become "WPG Storage" for our guild where we probably have well over 10,000 materials now, plus collector items.
With the addition of materials storage at the account storage for Factions it has become easier to collect materials. Hopefully Anet will expand that with each new chapter to include collector items, dyes, keys, etc to further free up account storage space.