O.K here's the write up straight from one of my text books:
The ventrogluteal site is the primary site for individuals over seven months old because there are no large nerves or blood vessels in the area. In addition, the ventrogluteal area is usually less fatty than the buttocks, meaning that more medication is administered directly to the muscle.
When the ventrogluteal site is used, the injection is made into the gluteus minimus and the gluteus medius muscles. The site is situated in a triangle within three palpable bony landmarks: the iliac crest, the anterior superior iliac crest and the greater trochanter of the femur.
THe site may be located by placing the palm of the hand on the lateral part of the greater trochanter with the index finger on the anterior superior iliac spine. Then the middle fingers are stretched dorsally as far along the iliac crest as possible. An alternative method of locating the ventrogluteal sit has been developed by Rhoda Brooke through her nursing experiences with adults and chilrdren. Whith this method it is not necessary to lay the nurs's hands on th body. Rather, the individual's anatomy is relied on more specifically. In Brooke's method, an imaginary line is drawn from the top of the iliac crest down to the trocanter. Then another line, parallel to the waistline is drawn from the anterior superior iliac spine (hip bone) to join the first line. The point of intersection is the ventrogluteal site. It is important to palpte the injection site; it should feel soft and fleshy. If it feels hard, the site is likely too close to the bone and will have to be adjusted accordingly.
An injection may be given into the ventogluteal site with the patient in a prone, supine or side-lying position. (Dugas et al., 1999, p.1153)
This is how I locate my site: I do the injection standing up in front of my mirror. I turn to the side so I can visulize the site in the mirror as well. I then find the greater trochanter (this is the top of your femur that inserts into the hip - you can find it easily by feeling around as you lift your leg up and down a bit). Once you've located that, just find the front of your pelvis on that side and follow the ridge (iliac crest) to the back. you can use your hand to guide imaginary lines that go from the two ends of the pelvis to the greater trochanter - an upside down triangle. Once you have an imaginary triangle traced find the middle. Push down in the area to ensure it is soft and not bony. If it is soft you can inject, so swab the area with alchohol, prepare your needle - I have used as small as insulin needles (I'm lean) to as large as 22 gauge and as long as 1" 1/2.
According to my drug guide you can inject as much as 5 CC at ONE TIME! in this site!
Once you guys try this site you will never want to go back to doing the dorsogluteal muscle - trust me! besides the quads, once you get your landmarking down it is the easiest site to access, and the safest, and best of all it doesn't affect any major muscles involved in walking, doing legs e.t.c.