Tips for taking photos at concerts?

I have a nikon d3000 with a 18-55mm and 70-300mm lens.
I'm going on holidays in two days for two concerts
and I'm just after a few tips and tricks for better photos.

Get close. Use aperture priority. Use high ISO.

Most concerts result in low light shots. Get as close as you can and try to stay at the low focal length of whatever lens you're going to use. This will allow you to stay at the wider end of the max aperture of your lens. You'll have to shoot at a higher ISO. I would start at 800 if lighting is bad. Shoot in Aperture priority and select the widest f/stop you can. Watch the meter and shutter speed. If your camera is selecting a shutter speed lower than the reciprocal of your focal length (shooting at 70mm but your camera wants to shoot at 1/60) then bump up your ISO. It's going to take a little practice shooting with lenses that don't allow you to open up for low light. If you're close enough to use flash and it's allowed, try rear curtain sync for some cool blurred shots.

Many concerts will not allow dslr cameras into their venue. Make sure the rules are clear before you go, or you may not end up going to the concert.

If you are taking pictures of hte band:
Use the 70-300 mm plus get as close as you can.
Typically, you will be too far from the band to get any great shots. So don't set your expectations too high. Concerts are very low light conditions, so pump up your ISO and use the smallest fstop number. This will give you the best chance of capturing sharp photos.
You are too far away to use the flash. So don't.
Another tip:
Concerts use a lot of crazy lights. Use these lights to your advantage. Use it as part of your creative process.

If you are using your camera to take pictures of your friends slamdancing into each other.
Use the flash. 18-55mm