So, as you should know by now, you can enchant books, and then use these books to enchant your tools and armor with an anvil. Since I have been trying to get 2 with Silk Touch to enchant my EU tools, I have done quite a bit of research on enchantment rates, percentages, and the like. In my search, I found this site, which has absolutely everything you would ever need to know, and I have been using it for that reason.
However, although there is ample information regarding vanilla enchanting, I haven't seen anything regarding the enchantments added by the mods in FTB. Sure, there are plenty of things telling what they do and what tiers they have, there is nothing regarding rates and percentages, which can be annoying when trying to get something specific.
To help solve this, I have created a spreadsheet for book enchanting. In addition to a condensed version of the information from the linked site, I have made an editable space for the mod enchantments. Currently, it has no additional information, but if you have anything you would like to add, feel free to do so. It has all the new enchantments that books can hold, and space for max rates and most efficient levels.
A link can be found here if you would like to contribute. Keep in mind that the sheet is for enchanting books, and not other equipment.