1) The content of your website should be user-friendly where user friendly means that it should be written in a manner where it is understandable by the people who visit your website.

2) There should be no grammatical mistakes in your text as it gives a very bad impression to the visitors of the website and it hurts the ranking of your website while the google bots crawl on your website.

3) Every website that sells something should have a clear refund policy written on the website.

4) To make sure that your customers trust you, please make sure that you have a About Us page on your website as this page makes your website trustworthy and people are more comfortable to place their orders.

5) Blogging is one of the most important aspect of SEO, start blogging but not in a manner that it looks like spam, remember that search engines, especially google loves blogs and it also helps you to bring more traffic to your website for free.

6) Once you write your own blog, remember to comment on other's blogs as this is the easiest way to let others know that you also exist and probability that others will comment on your blogs and/or start following your blogs will increase.

7) Write articles about the products that your offer, its free and simple but remember that search engines including google pick these articles quickly in their rankings and this can bring more traffic to your website then you can expect.

8) People who follow your blogs or pick your articles, start paying more attention towards them and assure that you comment on their blogs or give them extra content.

9) Start to share your articles and blogs on other webmasters.

10) Tell your friends to visit your article and if they find that information good, then ask them to use it as references.

11) 1 very important but very simple way to get free submission is to find a list of directories which are allowing free submissions like DMOZ.

12) With the submission of your website in unpaid directories you should also try to submit your website to paid directories.

13) A friend in need is a friend in deed, so start calling your friends and tell them to tag your website on social networks, as when they will do that other bloggers will also start doing it for you.

14) Join Better Business Bureau to improve the credibility of your name and company.

15) Website of your local chamber of commerce is very important, so get a link from it and you will definitely improve in the web ranking.

16) Submit the link of your website in local listings of your city and state.

17) List your website in the website of your local county's library

18) Try to get links from your business partners, retailers and/or manufacturers of your product, which will enhance the number of visitors plus the credibility of your company.

19) Once you are done with the website, launch an affiliate program, this thing might not help you to get a large number of links which may help you initially or provide you links with some good SEO value but they will obviously result with more link requests coming in future out of which few will be definitely important and having SEO value.

20) Try to use yahoo answers as a potential traffic bringing platform as many people search for a variety of stuff on it, by answering them correctly and not doing SPAMMING on it, you will be able to bring a lot of traffic on your website.

21) Use Google Groups and provide the link of your website where you think that will attract someone to visit your website.

22) If you are doing a real business then try to write about it on http://wikipedia.org remember that millions of people visit Wikipedia every day and articles written on Wikipedia are ranked very high on every search engine.

23) A majority of forums allow their members to leave signature links and/or personal profile links, a major quantity of people will visit those links if your content is not spammy is worthy to read. This will bring more traffic to your website and increase your sales volume.

24) Use amazon.com and other online stores where most of them are free to use, this will not just help you to bring direct customers but also secondary links

25) Another very simple and successful tip is to sell on www.eBay.com and offer to donate a particular amount of your profit to charity and you will find a lot of charity websites offering link exchange.

credits to : http://ezinearticles.com/?SEO-Basic-Requirements&id=2677608