If you’re going to Jerez, I lived and worked there for a year, I’d recommend:
Las Baderillas for rabo de toro, and corvina al ajillo;
Tabanco San Pablo for, arguably the best, serranito, try the ajo campero;
Tabanco Plateros for sherry, and simple tapas;
Tabanco El Pasaje for flamenco, some argue it started in Jerez and this is a great place to experience it;
My favourite bodega is Williams and Humbert, but the Gonzalez Byas is very good. Williams and Humbert‘s building is relativery modern but I like their sherries and brandy. González Byas is older and is very popular.
I’d also recommend the Real Escuela Andaluz del Arte Ecuestre, buy tickets in advance, they sell out.
Almost forgot there’s a driving tour through the vineyards of Jerez, unfortunately I don’t remember much about it other than you get to see a lot of interesting places.
Before I got my flat in Jerez I stayed in Puerto de Santa Maria, although others disagree, I didn‘t like it much, but that’s most likely because of my circumstances there rather than the town. As I said, others really like the place.