What to salvage? Explain please?
The quality of the salvage kit you use only affects chances on rare materials like Runes, sigills and Ectoplasm. I recommend using a Rare Kit on rare and exotic (if you have a Black lion kit (exotic kit) use it only for exotic) and a 25 charge basic salvage kit for everything else, including salvagable junk.
Material prices for low tier materials are rather high at the moment, especially T2 – T4 (Wool, cotton, linen) since Lv. 20 is right on the brink between T1 and T2 I’d recommend salvaging everything you don’t need for yourself for the chance of good raw materials.
If you want to experience crafting I advice you not to sell anything. I also recommend starting it right now. Levelling a crafting discipline also levels your character. However the quality of the gear is a bit lackluster. But it is very useful on Lv. 80 because you can make a full armor set of the stats you desire.
On the different materials:
Materials in GW2 are ordered in maily 6 Tiers. Inside your material storage they are ordered from top to bottom in their respective tab.
There are 4 types of basic mats: metal, wood, leather and cloth. These are used for all crafting disciplines and make up the bulk of the most recipes.
Then there are 8 types of fine materials: claws, bones, scales, fangs, totems, venom sacs, blood vials and piles of dust. These are used to determine the stats of crafted eqipment and are used for a multitude of utility recipes. Tier 6 Materials of this type are of rare quality.
Next are Rare materials: Slivers, fragments, shards, cores and Lodestones. they only have (the formerly named) 5 tiers and are used to craft mostly high quality sigills and runes. Some of them are quite valuable, keep an eye out for them.
The best general advice I can give you is: collect as much as you can. I can’t count the times I have kicked myself, because I sold a valuable Item, that I later needed for a nescessary crafting recipe. If you want to sell something, inform yourself ahead of time about what it is used for.
Pretty much what hornswroggle said but I will give you a quick summary in point form:
1 – Salvage almost everything.
2 – At your level however I would recommend against salving rare/exotic gear as you don’t have a chance at getting ectos. Leave that until about 73 (or is it 76 I always get this confused?). Or I should say only salvage rare gear that states on them that level it can be used at. Sell them at the TP, well at least see if they are worth anything more than a few silver, if so sell, otherwise salvage.
3 – Use the Basic Salvage Kit for whites, blues and greens. Use either the Mystic Salvage Kit (made at the mystic Forge and well worth it) or BLTC Salvage Kits for Rares and Exotics.
4 – I would also suggest buying the Copper Fed Salvage Kit if you can afford it or when you can to replace the Basic Kit for salvaging whites, blues and greens. Mainly for the convenience factor. You will never have to worry about running out of kits and having to visit a vendor all the time. It can also save a lot of inv space/time while you are out in the field.
Hope that helps and good luck!