Are you a member of IGN? You can join for $20- get a subscription to Blender/Maxim and, more importantly, get access to a guide for literally every important guide released. I use it constantly. And if you've never played a Metroid game before, a guide is really essential, since Metroid is more about exploration, using your visor to assess each area, and solving puzzles. Metroid is not a traditional FPS where you go into a room and start kicking ass. It's far more thoughtful and kind of like Zelda with a gun, which is why it's more appropriately a First Person Adventure. It's a hard game, but once you get used to the learning curve and what you need to do to accomplish your goals, it makes other traditional shooter games seem overly simplistic- at least IMO.
Good luck and, yes, you need a guide. Either buy a shiny $15 guide with pictures or join IGN.