If you want to look up an items use, visit the website: "platinumgod.uk" I believe. It shows every item and what the specific functions are. Try and watch some streams for the game on Twitch. Northernlion, CobaltStreak and iCasper are very good channels and very informative. Especially CobaltStreak. Deals with the Devil are better than Deals with the Angel. Azazel is the best character. Learn how to dodge and how enemies attack you. Also learn up on boss patterns. Explore every room on every floor (an exception being not exploring after the Womb floors. But I usually still do.) Save bombs and keys when you need them. Just because you see a golden chest, doesn't mean you should open it immediately. The game is all about timing, synergies and strategies. It is a tough game, no doubt. It took me about 100 hours on the Steam version of Wrath of the Lamb to get good. And I am definitely better now that I am using the X1 controller instead of a keyboard.

Realistically the game is all about trial and error, especially with items, some items are good, some are bad, and having synergies is great. Go watch some youtube videos if you do want to learn from others but for the most part you have to get a feel for the game

All I can say is good luck. If you get stuck, look up a bear bones guide, but I wouldn't recommend it personally.