When my colds haven't reached full swing, I generally workout. I lighten the load, but go through the movements just to get a little exercise. Exercise boosts the immune system, right. I also load up on vitamin C. Hope that helps.
keep training, just dont go balls to the wall. i generally take alot of vitamins anyways, but i do take extra vitamin c and extra zinc when i am sick. it works for me. make sure when you are at home your are sleeping, not out and about.
i remember when i was lifting with a head cold and doing squats and deadlifts in the same workout....it took some endurance to get thru the workout and the only thing i hope to do was to stay home from school.....NOT!!
usually when i feel a cold comin on, i fight as much as i can. for me tell-tell signs would be scratchy throat and "burning" nose. if i feel these, i know i have a cold acomin.