What's the general rule with salvaging things?

Like, if an item has non-perfect mods on them, is it just better just to use a normal salvage kit to get common mats? Or should a expert kit be used if you're trying to get rare mats? Also, what about id kits? Should I just id everything? Sorry if I sound like a noob, I just don't want to get ripped off. Finally, is there any guide/forum that has all this "stuff everyone needs to know?" Thanks in advance.

As a rule of thumb, salvage gold armors over 200g value and weapons with the "Highly salvageable item", and use expert kits most of the time.

Use the common kits only with low-level stuff and stuff that never salvages into rare materials like some trophies.

For example, most ghost remains (like Phantom Residue from ghosts in the underworld) salvage just into piles of dust and nothing else, so there's no need to waste expert salvage kit uses, you'll never get more materials or better materials by using expert kits.

Other trophies may salvage into rare materials. Use ALWAYS expert salvage kits on them.
I got the gems for my first Vabbian armor just by salvaging Geodes, Djinn essences, and weapons that look 'jeweled' or have gem-related names like Ruby daggers.

You can check the wiki when you have doubts about what an item may drop. There are many "contains" categories listing many items that may salvage into rare materials:
http://wiki.guildwars.com/wiki/Categ...fting_material

I ID whites if they are around 50 gold or more. You will be surprised as some double in value ;-)

ID kits increase the merchant value of all items they identify, even whites. Enemies of lvl15-20+ tend to drop items high level enough to beat the 4g per use cost of the ID kit, so ID all of those.

Mithran hit about all the vitals for salvaging. Most whites you find are usually worth as much or more for salvage or expert salvage than the gold worth of selling to the merchant, but you may not want to spend 5 mins at the trader after every mission selling a stack of wood for 1g apiece just to get 5g more on average per item. I just salvage the stuff that gives the pricey mats and quickly sell the rest. Also keep in mind that many "rare" mats are still dirt cheap at a trader and not worth an expert salvage kit, especially if the "common" mat for the item is something expensive.

Do make sure to hoard those Highly Salvagable inscriptions. Get them off a trash weapon, throw it on something that can give rubies or w/e and you can get a 20k payback if you are lucky.

You just reminded me on the subject of material and inscriptions.
I also take the inscriptions that increase the value of an item off of cheap items and put them on golds. Greater percentage return.
I sometimes take common materials to an Artisan and convert them into rare material and sell them at a profit. Eg., a Roll of Parchment can be made from Wood and a little gold. When the market is favourable I sell.