Ok so you get these different colored circles throughout the game and they are used to purchase bonus items. A good way to get a lot of red points is to scan all different kinds of lifeforms in cluding technology that has a mind of it's own like the machine turrets or the security cameras or the training drones also try scaning vehicles

Once you have both the X-Ray visor and Nova Beam, you can easily take out enemies such as Commando Pirates, Phazon Metroids and Metroid Hatchers.
Do this by switching to the X-Ray visor and locking on to the enemy, an extra scope should appear that highlights their weak spots. Take aim and fire at this area to quickly finish off the target.

Anyone who has M.P.3:Corruption knows that in the beggining you need to get into a secure channel with the G.F. (good guys) well you can also get wierd signals, here are 3 I found that seem to be found on only one channel code (so that it is easier I will give out the codes by a numbers going from left to right as 1-8).
Weird Alien Transmission is 8274
G.F. Secure Channel(later becomes Japanese Station Frequency)is:2751
Guitar Playing along with some Japanese Chat is:3648

Scan Everything including monsters. You will get a red emblem for each different monster you scan. Also it will often help you out when you are stuck.

An easy way to defeat the Metroid Hatcher is to have the Nova Beam and just keep on shooting the head of the creature and within a couple of blasts it will be defeated. The damage meter will not decrease if you do it this way but it still will kill it though trust me on this. (the strategy guide said this)