No Website or blog special an e-commerce site is complete without providing a way for customers to contact the Website owner. Luckily, this is an easy task to accomplish. Some WordPress themes for already contain a “Contact” page template. If your theme does not have one, there are a multitude of plugins that can add the functionality of contact form with only a click or two.
Following are three best options:
1. WordPress SpamFree contact form
After installation WP-SpamFree WordPress Spam Plugin, create a new page, switch to the HTML editing tab, and add the following tag:
<!– spamfree-contact –>

The WordPress SpamFree contact form is very nice and simple form for visitors and customers to contact you.
Download | WP-SpamFree WordPress Spam Plugin!
2. Contact Form 7

If you require more than a single contact form on your site, consider the Contact Form 7 plugin. It supports multiple forms, basic customization via simple markup language, CAPTCHA support, and spam filtering via Akismet.
Usage is similar to the WordPress SpamFree contact form. To add a new form, create a new page (not post) and add the following tag:
[contact-form 1 "Contact form 1"].
Download | Author Homepage | Plugin Homepage
3. cforms II
cforms is a powerful and feature rich form plugin for WordPress, offering convenient deployment of multiple Ajax driven contact forms throughout your blog or even on the same page. cforms II will not disappoint you. A small sample of the options are included here:
• Multiple forms
• AJAX-supported form submission
• File attachment support
• Timing and submission limits
• Widget support
Reference: WordPress 2.9 e-Commerce










