Itemization in Path of Exile is probably the second biggest shock after the massive passive skill tree. PoE’s economy, even in beta stage, is convoluted and involves much more than just gear. Skills are itemized, as will places, which are going to be itemized soon in the form of maps. New players are overloaded with this information, which makes it very hard to tell what is worth keeping and what is vendor trash.
It’s important to understand what drops you should be paying attention to, and which aren’t worth keeping. This guide will be offering a list ordered by pickup priority. It involves the obvious (rares, uniques) but also the less immediate such as 3-color-links to trade into chromatic (currency) or max implicit jewelry.
This guide assumes you want to pick stuff up for its general usefulness / market value. Your personal character needs at the moment should be max priority, and if you feel a blue (or a white) is an upgrade over what you’re wearing at the moment, then by all means pick it up!