Jennie Garth celebrates birthday and reality show with Shannen Doherty and Ian Ziering

It's been a busy 24 hours for Jennie Garth. Not only did she have a swanky birthday party on Thursday (April 19) to celebrate turning the big 4-0, but her CMT reality series "Jennie Garth: A Little Bit Country" debuts on Friday (April 20).

To celebrate the multiple festivities, Garth was joined at a Hollywood club by a couple of her old "Beverly Hills, 90210" pals - Shannen Doherty and Ian Ziering. Perhaps Doherty had some tips to share as she too is on her own reality show "Shannen Says."

The series focuses on Garth as she deals with life following her divorce from Peter Facinelli. The two were married for 11 years and only recently split up.

Garth tells the L.A. Times, "I don't like to call it a reality series...I don't look at it that way -- that term sort of conjures up bad images in my head. This is really a 'follow-doc.'"

Garth continues, "I never thought I'd be letting people into my life like this, but I'm glad I did."

"Jennie Garth: A Little Bit Country" airs at 9 p.m. ET on CMT.