Welcome aboard! We're glad you wish to help develop Wikipedia, and appreciate that for many, Wikipedia may appear to be a valuable resource for both promotion and SEO purposes.
To keep Wikipedia neutral and free from blatant promotion, we have many policies which you will need to familiarise yourself with.
If you would like to get a good overview of the project and how it works you could read through the introductory page which is found at Wikipedia:Contributing to Wikipedia. The same basic information can be seen at the Wikipedia:Tutorial. There is also Wikipedia:The Wikipedia Adventure, a 7-mission interactive guided tour which covers all the basics about editing and the expectations and norms of the Wikipedia community.
Editors who are compensated for their contributions must disclose their employer, client and affiliation with respect to any paid contributions. They must do this on their main user page, or on the talk page accompanying any paid contributions, or in edit summaries.
This transparency helps the Wikipedia community to understand and analyze the source and scope of paid editing, and to ensure that content originating from paid editors complies with Wikipedia's policies and guidelines.