They are a large close family. You get that part from the show you saw.
Basically the show is about a large Family that had what they thought was the best dad ever, along with a mom who ran the family.
The father passes away and the kids are left to try and pick up where he left off.
Along the way they discover that Dad wasn't as great as they thought, as they started to find things among his belongings (a picture in particular) that wasn't anyone in the family.
The business is hurting so they go seeking for assets and discover that he had a Girlfriend on the side. He had been with her a long time. She has a daughter and putting the pieces together, they surmise that its his daughter.
The family comes to terms with it and they welcome the new step daughter into the family.
At the end of season two, you find that she really isn't their step daughter, but the daughter of some hippy photographer the mother lived with in NY a long time ago.
Fast forward to this season we find out that the photo is actually a boy and they have his name. I didn't watch last night, so I'll leave it at that.
The rest of the show is individual plot lines.
Justin was in Afghanistan and ended up getting wounded. Got hooked on the drugs and now is living with mom to overcome his addictions. He fell for his not step-sister, although the family hasn't found out they are dating now.
Tommy became CEO of the fathers food company. The wife had trouble getting pregnant, finally does, has twins, one dies. They have a hard time getting over it, she goes to see the parents and doesn't return. He fools around with his secretary, she has an affair also, but they reconcile.
Kevin is the Gay brother who got married in the season finale. He's a lawyer, been in and out of relationships, but could never keep one. Finally ended up with the guy he married. Not really sure to describe his role in the Family. Most times he give advice, but he's not infallible.
Kitty left home years before and worked in NY as a Political analyst. After the father died, she came home and ended up staying. She met her new boyfriend and eventual husband Robert when he asked her to join his campaign for Presidential nominee. He lost, but is still a senator?
Sarah was also a CEO of the company. She was the stable one, married, two kids with a stay at home dad. The marriage broke up after her husband kissed the step sister, but that was only the straw, he felt smothered and unappreciated.
Norah is the mom. She's in everybodys business giving her opinion and trying to fix everything.
Holly was the fathers girlfriend on the side. After two seasons worth of drama, she bails out the failing family business and is now the Chairman of the company. Her daugher is Rebecca who is now fooling around with Justin.
Saul is the Uncle, who was in the closet and recently came out to Kevin. He made some bad decisions and put the company in the crapper. Somehow he continues to be the CFO?
That's the summary. I just looked on wikepedia and they have the details if your interested.
http://en.wikipedia.org/wiki/Brothers_&_Sisters_(2006_TV_series)
I'd rather not buy the first 2 seasons.
