I just wanted to add the following information:
When you call to get your self-declared* tax exempt 501(c)(7) status recognized by the IRS, you will likely need the following info to provide to your friendly tax person (and I sincerely mean friendly):
1. Your club's purpose from your bylaws or similar. If you don't have one, it can be pleasure and recreation involving homebrewing of beer
2. Your club's corporate form. In Illinois, there are not-for-profit corporations.
3. Primary source of money for club. Typical allowable sources are membership dues, meeting dues, etc.
4. Club's fiscal year. I recommend the calendar year.
5. Club's annual revenues. Revenues over $50,000/yr probably means that your are not eligible to be self-declared.
6. Your name and position in club, i.e., you have to be an officer of the club or an attorney for the club.
*Self-declared means that you don't have to file form 1024 and the $400 fee and also means that you won't get the IRS's formal letter of recognition. FOrm 1024 requires the same info.