As mentioned before, the most challenging aspect of making the switch to Unicode is finding the character you want among the tens of thousands available. In addition to the resources mentioned on the previous page, there are some useful tools to be found on the Unicode website.
Unicode characters are encoded with 16 data bits, and for this reason they are generally numbered using hexadecimal numbers (base 16). Hexadecimal numbers use the digits 0-9 and the letters A-F (representing the numbers 10-15). For some purposes you may have to convert the hexadecimal Unicode number to its decimal equivalent.
A guide to finding particular Unicode characters can be found here. This page also gives you access to the process for submitting characters if the character you want isn't yet included in Unicode.
Fonts
Two Unicode fonts that are commonly available on Windows computers are Lucida Sans Unicode (1,775 characters, including IPA) and Arial Unicode MS (over 50,000 characters, including East Asian logographs; ships with Office 2000 and up).
Code2000, a shareware Unicode font with over 34,000 characters, is available for free download ($5 if you keep it) by James Kass here. The quality is a little iffy (he's apparently not a font design professional), but it does have serifs for those who don't like the sans-serif version.
Code charts
From the Unicode website, you can download .pdf documents corresponding to "code charts" of Unicode subsets. Unlike the names list, these show the glyphs (characters) as well as their names.
The IPA code chart (.pdf)
Names list
The Unicode names list is available for searching both online and as a large text file. So, if you can guess what a particular character might be called, you can find the character number by searching this text file. Here is the online version; this version has links to the code charts which show what the glyphs look like. Here is the text file, which you can save to your local computer and search offline.
Inserting Unicode characters in various applications
Inserting Unicode characters is a bit more complex. The following is copied from the Unicode FAQ:
Q. How can I input any Unicode character if I know its hexadecimal code?
A. Some platforms have methods of hexadecimal entry; others have only decimal entry.
On Windows, there is a decimal input method: hold down the alt key while typing decimal digits on the numeric keypad. The ALT+decimal method requires the code from the encoding of the command prompt. To enter Unicode decimal values, you have to prefix the number with a 0 (zero). E.g. ALT+0163 is the pound sign ("£"), in decimal.
There is a hex-to-Unicode entry method that works with WordPad 2000, Office 2000 edit boxes, RichEdit controls in general, and in Microsoft Word 2002. To use it, type a character's hexadecimal code (in ASCII), making corrections if needed, and then type Alt+x after it. The hexadecimal code is replaced by the corresponding Unicode character. The Alt+x can be a toggle (as in the Microsoft Office XP). That is, type it once to convert the hex code to a character and type it again to convert the character back to a hex code. If the hex code is preceded by one or more hexadecimal digits, you will need to "select" the code so that the preceding hexadecimal characters aren't included in the code. The code can range up to the value 0x10FFFF (which is the highest character in the 17 planes of Unicode).
On the Macintosh with OS X, after activating the Hex input method, simply hold down the option key when typing the codes. After each fourth one, you get the character inserted in the document, and in newer software, the "Last Resort" font will be used if there is no regular font available for the character.
On Mac OS X 10.2 or later, there is a Unicode character pallet, which can let you click on and insert any Unicode character, including astral characters.
Note that this means that in current versions of Word, you can type Unicode characters in such places as the "find" field of a search-and-replace dialog using the Ctrl-x method described above.