LinkTradeskills is a pretty simple addon. It lets you right-click a name in chat, and select "Send Tradekills." That person will then be linked all of your tradeskills, letting them check out what you have and what materials would be needed for any one recipe. Further, to prevent linking your awesome 4/75 cooking right next to your 375/375 enchanting, the primary and secondary tradeskills are broken up into two options. You can send either your primary or your secondary tradeskills to whomever.
To make this work, all you need to do is open each tradeskill window once. It will then detect that you opened a window, get the link, and store it for later use. Once it has a record, you can then send the links to whomever by simply right-clicking their name in chat.
To reset the data, open the main game menu, and then go Interface Options --> AddOns --> Link Tradeskills. You can reset either just this character's data, or the entire account's data.
1.03: fixed a really stupid, simple, embarrassing bug that would watch tradeskill links from other players and record them as your own.
1.02: watches for low-rank secondary professions now, instead of just x/375. Will also watch for x/450.
This will now work with non-English locales, but will still be in the English localization/test.