Herman Park is OK, Memorial park is better for riding. The Picnic loop is the normal route for road bikes, pluse there are lots of MTB trails in the park.
Drop into Boone cycles or West end cycles for a visit and more information.
The weather is not very good for riding this weekend, the MTB trails will be closed becuase of the rain.
I'm moving this weekend so I cant be of any help as far as a riding partner is concerned.
There is a strong cycling community in Housto, Boones or West End can probably hook you up.