Whom should I vote for in other races

A mini game of thrones

The only comprehensive guide is the League of Women's Voters  http://www.VotersEdge.org site.  And that is only self-reported information provided by candidates and maybe ballot measure proponents.
A partial guide which just so happens to like me :), is http://sanleandrotalk.voxpublica.org/
The Green Party does put out a guide, but understandably it doesn't cover partisan races such as mine for Democratic County Central Committee. https://acgreens.wordpress.com/
Take the Green Party guide with a large helping of salt. When I ran for City Auditor, the Green Party guide got my party registration wrong. Turns out no one fact checked the person who wrote that section and they never provided it to candidates to fact check either.
Combine the above with glancing at the  candidate's websites to read their platform (if they even have one).  Google their names to see what legislation they supported or opposed.
So that leaves "slate card" mailers and single candidate mailers and newsletters from politicians. Interesting if you follow local politics but mostly progressive apple pie and motherhood.  Waste of good trees.
Easy to make the mistake that you can tease out the truth by comparing who endorses whom and comparing them to say the media editorial endorsements. Lots of group think and lots of underlying insider baseball that has 0 to do with qualifications for office.
For example I was puzzled by the endorsements of Sandre Swanson (State Senate) received vs Nancy Skinner's endorsement list until the underlying political favor trading was explained to me. Some of that has to do with the short "term-outs" of state politicians. They make informal deals with each other to trade off running for the same office. 
A mini Game of Thrones.
All of which is to emphasize the importance of choosing your party's (if you have one) Central Committee Members very carefully. Those members decide the endorsements of their  party for the general election non-partisan positions such as City Council.
Good luck fellow voter.