Adding a little more advice to the heap here ...
You need to let your management know that what they are asking you to develop is a constant, never-ending cycle of loading, scrubbing, cleansing, transformed and reporting on your company data. As you continue to work with your data you will be able to reduce the time it takes (hopefully) in which you begin your process until your users can run their reports.
Your existing "live" systems are often referred to as OLTP (On-Line Transaction Processing) systems, which help keep your company in business. What you have been asked to create is a completely different perspective of the information and data that these systems create. The (most likely) company wide set of data gets "Extracted, Loaded and Transformed" (ETL) into an OLAP (On-Line Analytical Processing) system, which is what your SSRS Reports will run against.
References to get you started:
The Data Warehousing Information Center
This site should allow you to get a grasp of all these new terms and concepts.
Also any Data warehousing books written or co-written by Ralph Kimball will do you well. Ralph Kimball, is an author on the subject of data warehousing and business intelligence. He is known for long-term convictions that data warehouses must be designed to be understandable and fast. His methodology, also known as dimensional modeling or the Kimball methodology, is frequently used to allow sharing of conformed dimensions.
He writes the "Data Warehouse Designer" column for Intelligent Enterprise magazine and is the author of best-selling books The Data Warehouse Lifecycle Toolkit and the Data Warehouse Toolkit published by Wiley and Sons. He is listed in the Database Hall of Fame.
The key to you having a successful go at this is that Management is aware of what they currently have versus what that have asked for. The second, and hardest part, is when they realize how much work is involved in getting there.
Keep us posted on your progress,
MCITP: DBA, MCSE, MCTS: SQL 2005, OCP