Remember for a fee, now you can perform your own land search online at the ministry of lands and urban development website for some parts of the country. (Online account registration at ecitizen.go.ke with National ID number and scanned passport photo is required prior to proceeding to the land search page)
eCitizen Dashboard Screen after login
Registries that are online as of Dec 2, 2016 are listed.
An article titled Buying Land in Kenya In 10 Steps by Timothy Wahome, a lecturer in finance at Africa Nazarene University gives great advice on how to purchase land in Kenya, which also generally applies to property.
The following videos also provide helpful insight on land acquisition by a Kenyan who was formerly in the diaspora.