Ugh, food poisoning SUCKS. Don't beat yourself up over missing a run. It happens. And just for reference, one should never punish with combining runs, no matter how close or important a race may be (meaning, if you missed a 3 mile run, and your next day's run is supposed to be a 5 miler, doesn't mean you do 8. Theoretically, you should push everything back one day, or if you're further along, some people say split the difference and do a 4 miler).
Are you following a running plan? If you're not, you can try
www.halhigdon.com or one of the plans at
www.beginnertriathlete.com (I blog/train there as the same SN and there are a couple other GC'rs there too! I truly love my training log there because it does nifty graphs) and I think that
www.runnersworld.com has blogs and plans too.
I've also gotta plug the Chi Running technique. It turned me from a whining fat miserable 13+ minute mile run hater, to a whining somewhat chubby occasionally manic 9 or less minute mile marathoner. It is great if you're starting from zero run experience. If you know what you're doing, then it probably won't benefit you, and some of the advice is a bit on the granola side but the advice on form and such was really helpful for me. The book is called ChiRuning and the writer is Danny Dreyer and it can be found at any book store or on Amazon.