Is it better to charge my camera battery before first use?

It won't hurt, but it'll also be okay to just use it. Lithium batteries (like that used by this camera) last longest when stored at around 40% charge, so hopefully that's what they do before they put them in the box. So, it's probably fine to take it out and play right away for a while, but you won't get as long of a first trial period as if you charge it fully first.

Many people find it valuable to have a second battery. I recommend buying one right with your new camera purchase. Then, you can start using one while you charge up the other.

If you're intending to do a firmware upgrade, do the full charge before starting that.

Actually, it is best to keep your battery between 57-77 degrees Fahrenheit. Fully charge your new battery before first use. After fully charging and discharging your new battery three (3) times, it will reach its' optimum charge capacity. This info come directly from Cameron Sino, one of the leading battery manufacturers with over 30,000 types of batteries.