I want to put an object into a picture. How do I get rid of the background on the object (which is a part of a jpeg picture). Thanks in advance.

It would help to know what software you'll be using. Assuming you have Photoshop, first you'll have to save the pic in a format that supports alpha channels (.psd, .tif, .png, etc). Once that's done, you can simply use the eraser tool to remove the background. Now, select all, open your other pic, and paste into a new layer. Scale and position the new layer, until you're happy with it, then save in your preferred format. I guess the steps will be similar using other software. Please let us know if you found someone's advice to be helpful.

The first thing you want to do, regardless of software, is to make a backup copy of the photo you plan to work on. This way, if you 'screw up', you'll have something to fall back on. Also, if the software has it, I use the polygonal lasso tool to remove most backgrounds. Add about 1 or 2 pixels of 'feather' and click away. Be sure to zoom in for more accuracy. With Photoshop, after outlining the image, invert the selection and click 'Delete'. This will clear the background. Sometimes a second click will help. Depending upon what type of background you have, there could be other, better options. If it's a solid color background, either the 'Background Eraser' tool or the 'Select Color Range' tool might work easier. If you have it, the 'Extract' tool works wonders. If you don't have Photoshop, try using Paint.NET (free). It's a great up and coming photo editor! Don't squat with your spurs on!