The following advice is not meant to scare but to educate, because you should know that Comic-Con is a BEAST. However, if you're prepared and enter with realistic expectations you'll have a better time.
HOTELS
Now that you have your tickets, get your hotel room ASAP. Some people have had reservations for months now, and this new influx of people will only make finding a room harder. Rooms near the convention center are expensive and traffic is bad during the con, so I highly recommend getting a hotel further out near a trolley station (or be prepared to park at a trolley station in the morning). You'll have to buy a multipass, but the trolleys are an effective way to get around since they roll through frequently.
FOOD AND OTHER NECESSITIES
There are many places to eat in and around the con, but expect the quality to vary, everything to be overpriced, and lines like everywhere else. Get a local restaurant map if you want to find some decent places since you'll have to go into downtown San Diego. It's also wise to pack a small lunch, snacks, water and any medicine you might need.
EXHIBITOR FLOOR
Bring your own sturdy backpack/bag and do your shopping early on. Some exclusives are fairly limited, so be prepared to get the ones that you really want first. As well, if you get a bulk of the shopping out of the way quickly you can focus on the rest of the con. Most of the time this area will be crowded, especially around display exhibitors who use their space to promote upcoming movies/shows/whatever. Take note of these exhibitors and avoid them (unless you want to see what they're shilling).
ROOMS/HALLS/PANELS/ETC
Comic-Con will be packed. Make a list of the panels/events that you want to attend and create a realistic schedule from that, but be ready to be flexible. You can easily have fun wandering about and going to random things, but you may have to put in a bit of effort if you want to do specific things. Do expect lines and wait times for popular panels or even panels before popular panels. Just remember to pace yourself, don't go overboard, and have fun.