Local and Online Instrument Shop Recommendations
Violin, viola, & cello: I highly recommend Loveland in Santa Rosa to all Sonoma County local violin, viola, and cello players looking to purchase, rent, or repair an instrument; their quality, level of care, and affordable pricing are unmatched. Good options outside of Sonoma County include Ifshin Violins, Johnson Strings, and Shar Music.
Piano & guitar: Guitar shops usually have a nice array of quality guitars to choose from and some have decent electric pianos as well. Sonoma County local shops I recommend are Stanroy, Bananas at Large, and People's Music (this is a non-exhaustive list). O'Hara Guitars is a well respected local guitar repair shop. Sweetwater stands head and shoulders above all online guitar and electric piano retailers in both quality and expert advice; if you aren't able to buy what you need locally, go there. For local acoustic piano tuning and repair, I highly recommend Beverly Wells at Piano Craft.
Recorder: My favorite brands for high quality beginning level plastic recorders are Aulos and Yamaha, available in many locations local and online. For intermediate or advanced players shopping for a high quality wooden recorder, check out Moeck and Kung.