As you may have learned from your chat with Mr. Tonson, literacy in eighteenth-century England tended to be higher among the upper and middle classes. Still, literature was available that could be enjoyed by all classes and both genders.
Literature aimed at upper classes tended to focus on religion or social problems. The wealthy considered themselves the only rightful purveyors of social instruction, and their literature reflected this idea. Books focusing on how to better oneself-- especially betterment through religion-- were popular.
Significant advances for women's rights were also beginning to take root in upper-class texts. A great deal of controversy occurred because outspoken upper-class women were speaking out and insisting to the men that they be heard.
Middle-class literature generally focused on the problems of the working class. Because the rich desired to keep their present social class system--they did greatly benefit from it after all-- they were often frowned upon by those who had to work hard for their living. Because upper classes were known by this vanity and bigotry, satires and other forms of mockery found a willing audience in the middle class.
Another concept present in middle-class literature is "upward mobility," the idea that a person could transcend his or her current class situation in favor of a higher one. This is especially true for literature aimed at women, who could advance their stature by marrying a man of a higher class.
Literature specifically intended for lower classes was much more rare. Yet much writing focused on an equalizing of the classes, an idea that would certainly appeal to members of the struggling lower class. Satire was one such genre; authors often portrayed the vices of the upper classes as being just as bad, if not worse, than the faults of the lower class. Aside from literature, there were cheap newspapers and chapbooks for the few lower classes that could read.
Stories of "fallen women" rising above their stature were popular with female readers, an idea that lower-class women would no doubt approve of. The sordid details often contained in these stories also appealed to men.
Of course, the Bible remained a staple in everyone's literary diet. Upper class men and women were able to read it for themselves, but even those people who were illiterate or could not afford a copy of their own still knew the contents chapter-and-verse.
But that's enough general overview of the situation. You're here for specific suggestions, after all! So please, go ahead and