Wikipedia - Wikipedia is one of the best source to search for facts and information less known to the public. Personally, most of my inspirations originated from Wiki.

Google - Most of the puzzles contain hidden information or riddle referring to a person, a formula, a place, or even a myth. Google is always the best place to search for certain keywords you have uncovered from the puzzle.

WordSmith.org - Puzzles are likely to contain anagrams, and it might take you plenty hours before uncovering the true meaning of an anagrammed sentence. WordSmith.org provides one of the best anagramming program available on the Internet, they call it Internet Anagram Server.

Adobe Photoshop - Sometimes, some image-based puzzle requires you to perform certain processing before being able to uncover the hidden messages. Photoshop comes in handy, it has some very unique features in image processing which many puzzlers love to apply on image-based puzzles.

Ascii Table - Many of the BizFantast puzzles were based on ascii encoding, with some minor variations in-between. The Ascii table is a very nice reference guide to Ascii mapping and numbering.