what are all thing to do while taking a photo?

Yes, after taking the advise of all the other commenters, you have to start to understand your surrounding. Lighting is very important. Harsh light can cause overexposure. Too little light causes underexposures. Even if you use flash, you have to be careful too. Instead of using flash, maybe you can also change the ISO of your camera to another level - 100 or more. But, remember this can cause your pictures to become grainy. When you are taking pictures, make sure your hands are steady. If not, then use a tripod to help you.

Read the manual from cover to cover. Then take out your camera and read it again with the manual doing what the manual tells you to do to set up the camera. Read the section on the batteries. IF they need to be charged then charge them for 24 hours before putting them into your camera. Many cameras require you to set up the camera using the menu. Once this is done you are ready to take pictures. Take lots of photos, with digital you can delete the ones you do not want.

Uuummm...make sure the weather is nice, don't be around water, don't be around children who LOVE the water, always have the strap around your wrist just in case you drop it, make sure the time stamped date is correct and experiment. Now, for those shots you know should make into your family album, try changing the settings from coloured to Septia or black and white. Septia gives it a nice "antique" look. Another big important MUST, sign up (if you haven't already) for an online photo album...like Shutterfly.com I've lost so many computers and sometimes I forget to upload my photos on there. So many memories were lost because I didn't take the time to make sure they were secured.

Always be sure that before you start working with the camera, there will be an user manual read it well before you use it. Before taking the camera out for taking a snap or picture, make sure you have the batteries in it. Also if you have a memory card or memory stick slot, then make sure you have it in place, if you have purchased one. Depending upon the brand and camera there are lots of online help. Check them out.