Most states allow access to the full text of bills from the current legislative session and you can often search back several years. However, other materials such as hearings, debates, and reports are often more difficult to locate. The Library of Congress provides its Guide to Law Online, with links to free web-based state legislative history resources for each of the Fifty States.
New York State Legislature Bills and Chapter Laws - from 1995 to present. Use the drop down on the left to select Bills or Chapter Laws.
New York State Assembly Bills - 1999 to present.
New York Senate Bills and Hearing Transcripts - use the drop down to select Bills or Hearings (search by month, year, sponsor, and keyword).
New York State Archives Bill Jackets - from 1993 - 2021. Click view all, and filter by year. Narrow by bill number, chapter law, or keyword.