Dunno what people are looking for in poe, and don't know the shorthand yet so looking at the forum I'm a little lost..

What's of value? What do people look for mostly for trades?

Get POE awakened. It price checks items in game. Also, look at poe.ninja website. It shows top items and their prices

Once you start it, CTRL+D while hovering over an item.

install gentoo as well

I use poe ninja and look at the charts, everything is listed by type.

Thanks guys!

This is for Awakened. When launched, nothing happens. You'd have to check the notification area for the icon. But if you're in the game, just hover over the item and press CTRL+D, an overlay will pop up. You'll have to select the stats you want to price and a range. Be sure to check slightly lower quality compared to the one you wish to sell.
Also watch for rate limit. If you check too many things at once, it'll lock you out briefly. Kind of like how the "connection errors" were when joining game too fast on D2R.

POEninja is nice because they have things in categories and lists. So for currency items, fragments, league specific items/maps/currency, you can always just go and check the list.

Also if you use Chrome, installed the Better PathOfExile Trading extension. Little QoL features. It will show conversion of currency. Example: If an item is listed as 1.5 Exalts, it will display current market conversion to Chaos. ( 1 Exalt + 73 Chaos ) Easy so you don't have to look it up and calculate yourself.

Watch in trade, something when something is 1 Ex, the trade site values that less some set number. Unsure of what that number is. Possibly default to 100 Chaos? So if it's price low to high, it will show 1 Ex items before 100 C items. Also scroll down some and see that the asking price goes up. Better PoE Trader makes it real easy to read and process.