An effective sales plan will help you target your customer base and aid you in closing the deal. You will need to identify who purchases from you, their wants and needs, and how to effectively sell to them. Use the tips and tools from these sites to build your sales base.
Entrepreneur.com provides sales tools, presentation tips, prospecting resources, and more.
Fast Company, published 15 times a year, offers tips for building your bottom line through solid sales.
Inc.com offers information on making cold calls, developing communication skills, and building your customer base. Inc.com's information is topical and changes regularly.
Also, read the best customer service practices section of their website.