CD quality is 16bit/44.1KHz sampling. DVD quality is 24bit/48KHz sampling. SAC audio is 1bit DSD/2.8 Mhz. Basically you get to decide on what is the ideal rate for you, then either record or convert the files you have.

Many audio engineers will record in the sampling rate of the destination format or multiply that destination format by 2. For instance, I usually record at 24 bit/88.2K and then convert down to CD upon completion of the project when I burn the media for the client. Yes files get big. That's why all the kids these days use compressed MP3 files.

John has provided good information, as usual. One small correction, though. The standard for audio on regular DVD is 16bit/48kHz. DVD-Audio and Blu-ray discs allow 24-bit/192kHz.

Have fun!

Rob

Some prefer to recording at the same format as the target to avoid sample rate conversion (for example record at 44.1k/16bits for a CD).
The other way is to record at the highest format possible and sample rate down to your target format. (for example record at 96k/24bits).
I prefer the later.
First of all, recording at 16 bits does not give you enough dynamic range (IMHO), specially if you record live instruments. Recording at 24 bits gives you enough headroom so you don't need to compress your signals when you record.
Secondly, there are some very good sample rate conversion algorithms today (for example Izotope's) that do an excellent job of sampling down and some very good dithering algorithms also to convert from 24 to 16 bits.
Thirdly, storage is cheaper and cheaper and CPUs are faster and faster; so what if your files are bigger and need more CPU power to handle.

i got the best mic ever here