Probate, Code violation, preforeclosure etc. list source

Hi everybody, i have been targeting gerenal leada and the contracts are few and far between. In this community I have come across a lot of suggestions about targeting niche lists. I wanted to know about where i can get these lists? those that are regularly updated. Are these only available if one visits the county clerk or is there an online way as well?

Also would like suggestions on the specific niche lists, if there are more to be targeted than named above.

Thanks in advance