Oak Kitchen doors - cleaning

Can any one tell me the best way to clean the doors on my kitchen units? They are light oak with varnish - I guess. Just have a feeling that various detergents and cleaning stuff may cause some damage to the finish.
Thanks in advance.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.