A super cool tip I recently learned: if you hold shift and right click an empty area of a folder, "open command prompt here" should appear in the context menu. Saves a lot of hassle from running cmd.exe and then trying to navigate to your folder via cd, dir, and tab completion.
I find Crystal Tile 2 very convenient for looking at tiles, but everyone has personal preferences.
For long Japanese tables with thousands of entries, I actually use... Microsoft Excel. In col A I have a long list of integers. In col B I use =DEC2HEX to convert to hex. Col C is the character itself, and col D is a concatenation in the format of "hex = character" I copy col D to a text file and save that as my table. One reason for using excel is that, for instance, if I accidentally skip a character, that means ALL the following offsets need to be shifted, which is trivial in Excel (just drag cells around).
I second Monkey Moore as being a useful tool. It's great for finding the hiragana in a game. Pretty sure it outputs tables in UTF-8, though a lot of other tools expect S-JIS, so be aware of that.