Sorry to disagree, but the directions spacial linked to are incomplete as I believe it is missing a step. The air you draw into the syringe and then push into the vial is merely to make sure you have as little air in the syringe as possible when you draw out the medicine. It doesn't really matter how much you push into the vial.
Also, you don't mention which kind of vials you have. If you have the kind with a glass top that needs to be snapped off, you should really use filter needles to withdraw the E to make sure you don't accidentally inject yourself with glass shards from snapping off the top. Also, there are vial openers that would probably be worth getting. Once you have enough E in the syringe, try to get big air bubbles out, but as long as you aren't injecting into a vein or artery, small air bubbles will not be a problem.
The missing step is to pull back on the syringe plunger once you have the needle in to make sure you haven't hit an arteriole or venule. If you see blood in the syringe when you pull back, withdraw the needle and use another injection site.
Try this link (he is injecting T but it's pretty clear and has all the steps) for videos and diagrams of injections sites (front of the thigh or buttock is best, avoid the lateral thigh since it's better not to have to penetrate the IT band, which is usually more painful):
or this link:
http://www.youtube.com/results?search_query=estrogen+injections&oq=estrogen+injections&aq=f&aqi=&aql=&gs_sm=e&gs_upl=426376l434036l0l448074l19l19l0l10l10l1l286l1646l0.6.3l9l0
