How to put seller information to product page?

Edit this file: app/design/frontend/THEME_PACKAGE/THEME_NAMEtemplate/catalog/product/view.phtml. Replace THEME_PACKAGE and THEME_NAME by your theme info.

Add this code to that file where you want to display seller information.

<?php $_vendor = Mage::getModel('vendors/vendor')->load($_product->getVendorId());?>
<img src="<?php echo Mage::getBaseUrl('media').$_vendor->getLogo()?>" /><br />
<label>Title:</label><?php echo $_vendor->getTitle()?><br />
<label>Company:</label><?php echo $_vendor->getCompany()?><br />
<label>Telephone:</label><?php echo $_vendor->getTelephone()?><br />
<label>Address:</label><?php echo $_vendor->getAddress()?><br />
<label>City:</label><?php echo $_vendor->getCity()?><br />