A quick remark about two books I’ve discovered recently.
Alexander M. Schenker’s The Dawn of Slavic (New Haven: Yale University Press, 1995) is concerned with the historical and cultural events of Slavic ethnogenesis, but it also has such an extensive presentation of Old Church Slavonic that it may be fairly counted among OCS primers, comparing quality-wise with Gardiner’s not so hot but still somewhat useful Old Church Slavonic: An Elementary Grammar (Cambridge University Press, 1984). If you follow the link to Amazon.com’s page for Schenker’s book, ignore the sole reviewer, who is simply a moron.
Robert I. Binnick’s Time and the Verb (Oxford University Press, 1991), surely an allusion to the first of T.S. Eliot’s Four Quartets, is the most amusingly titled linguistics work I have encountered yet. It is an introduction to tense and aspect.