Web Site Design Begins With the Pages
A site map is a list of links to all the pages comprising the web site
design and it gives search engine spiders an easy path to follow to
collect all the pages in the site.
It is fundamentally important to choose keywords that will optimise your
pages and differentiate this web site design from other competing ones.
In the past meta tags were more important than they usually are now.
Because the internet has become more competitive web designers have used
methods to get their sites listed which have compromised the usefulness
of the meta tags, and consequently the search engines have come to rely
less on them as a means of evaluating the relevance of a website.
However, the use of meta tags does still provide a useful layout tool for
web page design - enabling the designer to keep a focus on which key
words are being designed into this page - and how the individual pages
are tying together into a unified whole as a website.
When the search engine spider goes through your website it is looking for
links to other pages, so make sure every page of the site has links to
the other pages. It is advisable to work out which engines are most useful
for marketing the particular site and then optimise the site content, key
words, and meta tags as necessary.

Other Resources
eTail Central ecommerce Web Site Design of Online Shop