Don't want to waste your rescue group's financial resources on artwork? There are a couple of websites that make it very easy to create a logo free of charge. You'll still want to take a little time to have an idea of what you want first. Try googling search phrases like 'new logo trends' "choosing logo colors" "choosing logo styles". There is a wealth on information available to help you decide how to evoke the feeling you want from your branding.
Online Logo Maker
Logo Joy - costs $65 but well worth it