You want Gardiner's Sign List. It's not really a catalog of all signs but it catalogs pretty much all the common ones, which is the vast majority of signs that appear more than once in the corpus of Middle Egyptian. There are other alternatives like the Budge Reference, which collates more signs than Gardiner does, but Gardiner's list is much easier to use, is not significantly less complete, and is generally more useful. For an actual student of Middle Egyptian Gardiner is more useful on a regular basis, since he includes variations and so forth and his sign list is more neatly organized. You can find at least a form of Gardiner's list for free online, but to my knowledge it lacks the full form of Gardiner's list, with the included variations and vertical-horizontal readings. It's not an especially hard book to chase down, though