Spreadsheet Integration and Formula Setup

I need assistance in combining multiple spreadsheets related to sales data and adding necessary formulas to calculate key metrics.

Requirements:
- Combine sales data from various spreadsheets into a single, organized sheet.
- Set up formulas to calculate:
- Total sales
- Average sales per month
- Sales growth percentage
- Sales data is updated weekly, so the solution should be easy to update.

Ideal Skills and Experience:
- Proficiency in spreadsheet software (Excel, Google Sheets, etc.)
- Experience with data integration and formula creation
- Attention to detail and strong organizational skills
- Ability to deliver a user-friendly and maintainable solution