For guy who wants to be a master of network (WAN/LAN, no matter it's black, red or white), without help of various off-the-shelf classical network utilities for multipurpose uses, I'm afraid your level will stay in the DOS era of last century forever. I mean, in that case, even it was you invented the whole Internet, you could not do anything interesting or exciting.

Head First Data Analysis will teach you how to use a variety of data processing tools (such as Excel, 0penoffice, R) to organize and sort out data, in order to play the role and value of data incisively and vividly.

Colour Contrast Analyser's main purpose is to detect foreground and background colors at the same time to see their matched-degree, make sure if they provide a good color visibility. It's especially suitable for web and graphic designers.