Hi
SEO - Search Engine Optimizations is divided into two parts
1)ON-Page & 2) OFF-Page
If you are designing a website than you have to be careful that you design does not conflict it. All possibles on page things be done like TITLE, DESCRIPTIONS, META TAGS, META DESCRIPTIONS, CONTENT & ALT TAGS.
Coming to the OFF- Page you can Do many things and this is the place where you should be careful because if you don’t know what to do than you can waste your all efforts.
try to make back links with the high page ranking website, and try to get the back links from the website that provides the same services as you do.
Try to promote your Content by writing Article, Blogging and many thing.