There has been lot of misconception regarding BI being just Data Warehousing. However, Business Intelligence is not just Data Warehousing, or star schema or snowflake schema. Its a collection of tools and technologies to which helps convert raw data into actionable information. Data Warehousing is a part of Business Intelligence.
To understand Business Intelligence, its application, role of data warehousing, Business usage a beginner in this area should read books which introduces BI in simple to understand language.
Following books are the starting point to acquire this knowledge.