Johnny,
Sorry didn't see sooner, had a busy day at work.
To answer your questions:
I researched several partnerships over the internet and contacted a few via email and phone to see which one I was most comfortable with. I'm sure a few others on here know far more than me and can point you in the right direction. I did discover quite a few partnerships I would describe as ripoffs or even tax writeoffs, so be careful.
I own or owned small percentages in several horses. I was up to 4 before a few got claimed away, but I was confused as to what I actually had invested in each. I currently have a parts of two horses, that are low level claimers based at Penn. Honestly, I don't know the exact percentages off the top of my head, but I can tell you it is just small discretionary income and not something I consider life-changing.