These websites are chosen for reliable information.  I have not personally reviewed every article on these sites. 
​

UpToDate

http://www.uptodate.com/contents/search

CDC - Centers for Disease Control and Prevention

http://www.cdc.gov/

AAFP

http://familydoctor.org/familydoctor/en.html

Mayo Clinic

http://www.mayoclinic.com/health-information/

Patient Education Center

www.PatientEdRx.com

ALS Association
http://www.alsa.org/about-als/