What makes one eligible for a 1099...would it be 'anyone' doing work that we pay them for? Programmers that work remotely from another state....to a janitor that comes 4 times a month?
Take a look at the IRS 1099 Instructions for who you should file a 1099 - http://www.irs.gov/pub/irs-pdf/i1099msc.pdf
To determine if workers are independent contractors or employees and whether you should issue a 1099 or W-2go to the IRS website. Other IRS resources include IRS Publication 15-A, Employer's Supplemental Tax Guide, Publication 1779, Independent Contractor or Employee, and Form SS-8, Determination of Worker Status.
If you are talking about the state 1099, see http://www.ftb.ca.gov/individuals/faq/net/908.shtml
There is a fine line between contractors and employees. I have found that California has stricter employee vs contractor laws than most other states and even than federal law. Each job would need to be looked at separately and you need to consider financial. behavioral and type of relationship.
Texas actually has a really good article on their employers' website: http://www.twc.state.tx.us/news/efte/appx_d_irs_ic_test.html. One of the major things to look for though is if they truly work for themselves and could do other jobs at the same time for other clients. For example, does the janitor work for a cleaning company? Does he/she clean for others?
If they are truly contractors, you would need to issue a 1099 if you paid them over a specific amount (think it's $600 annually).