Best time to visit Naga City is during the Penafrancia festival in September! If you're not able to visit during that time, then October to March is fine. The hottest months are April & May. Rainy season begins in June.
Prices are pretty much the same as in Manila when it comes to food. Lodging might be cheaper in some respects.
There are several banks in Centro with ATMs but it's always best to already have your cash before you get to Naga City.
Wifi can be found in many places in the city for free. There are numerous internet cafes throughout but no point if you have a laptop and can go to a free hotspot. The only downside is no outlets to plug in your laptop.
Penafrancia Festival happens on the 3rd Saturday of September. So, if you want to see it, try to get there a week or more in advance. Many Bicolanos will travel to Naga during this time to witness the festival and visit with relatives. The fiesta day happens towards the end of the festival so that's why I recommend you go to Naga a week or more ahead of time.
Fiesta/Festival time a great way to experience the culture, food and meet lots of happy locals!
There are many other fiestas that happen throughout the province during the year so no matter when you go to Naga City, there is probably a festival/fiesta going on in one of the small towns nearby.
The buses are new or almost new and they provide a very good service! You will arrive in the bus terminal next to the SM mall that is being constructed. From there, you can find many jeepneys or tricycles that can take you downtown to your hotel.
Lolo's bar is regarded as a good place for local music. There are some karaoke bars in the city too.
Movie houses aren't really a big deal anymore as there are many pirated dvd vendors around the city and many people just buy their movies from there since they are so cheap.
Sadly, there is no National Bookstore in the city. There will probably be one once the SM mall is completed later this year. You can try buying books/magazines at Booksale in the E-mall or LCC shopping center.