I would suggest rather than gathering external data have the newsletter packed with company's internal information such as:
- Events/special days - write-up with lots of photographs
- Worklife balance - out of the ordinary activities/hobbies that one pursues
- Focus on employees who have been with the firm for 3/5 years or more
- Client/internal Awards
- Write-up on teams that has exceeded client’s expectations
- B'day/Anniversary list
- Family Column - Significant work/contribution/achievement of employee's family members
- News - Industry/local
- Articles – contributed by employees
By reading such information on company’s newsletter will make employees feel that this is designed just for them and is different!!!
Which Industry do you work for?
You can collect Industry/business news from the website of local/national news papers. As far as Articles are concerned have your employees contribute some, gather some online or from magazines like Human Capital, Human Factor, HBR, Business Week etc.
You can also include a puzzle where you can reward first 2 correct entries.
Let me know if you need anything specific.