Welcome
garciadiego
You have to revise that important subject by visiting the following links :
http://www.enotes.com/nursing-encycl...ular-injection
http://nursing.about.com/od/educatio...Minjection.htm
or you can use the technique of quadrants :
1. For example Divide the the right buttock into 4 imaginary quadrants
2. Focus on the outer upper squire and you can divide it into 4 imaginary quadrants.
3. Finally inject the needle as dart using 90 degree angle
4. Aspirate, if there is no blood this means that you are in the correct route then pouch the medication slowly then don't hesitate to remove the needle quickly and put swab of alcohol on the injection site.
good luck