Personalize it. Don't send a generic email all about yourself. Focus on what you and the recipient have in common. Mention the group you found her through on LinkedIn or something specific you know and admire about her company.
Demonstrate value. What do you have to offer the recipient? Be upfront about what you can give her and why she should respond.
Include a call to action. Tell her what it is you want her to do: email you back, reach out to set up a call, or forward your email to someone else.
Keep it clear. As with all email, make it clear, articulate, typo-free, and to the point.
I'm a multi-disciplinary designer-strategist at HP. My passion is whole product design: the seamless integration of HW+SW+Web to deliver compelling experiences to users. I'm currently swimming upstream to bring Web 2.0-style community participation to HP's consumer printing business.