1. Influenza is airborne. You can catch it from contact with contaminated surfaces too (like a doorknob) but the primary mode of transmission is respiratory droplets. You're considered exposed if you've been within six feet of a patient because of this.
2. The assumed infectious period for influenza victims is 24 hours prior to symptoms through seven days after. 
3. Influenza can persist in the environment for a very long time. How long exactly can vary from hours to months, depending on the specific environmental conditions. "Cold and dry" is better (for the flu) than "hot and humid" which is why there are more flu outbreaks in the winter. However, it's a fair bet that if a flu patient sneezed in their hands, then opened a door, and then you handled that door knob hours later and proceeded to touch your face, you'd be exposed. This is why handwashing is critical even if you can catch it from simply breathing.
4. N95 masks are good protection, but not perfect. If someone sneezes, they'll stop the airborne particles of spit. You really don't want to breathe a flu patient's airborne particles of spit. However, flu virus by itself is small enough to go right through the mask. And you can catch the flu from virus that contacts your eyes. So the masks are some protection, just not complete protection. 
5. Pandemic strains of flu originate when influenza mutates or combines with animal influenza to create a form of flu that no one has any immunity to. This happens naturally and isn't necessarily caused by terrorism. There's a lot of conspiracy theories out there right now, but this could be an entirely natural virus. Influenza doesn't need Al Qaeda to mutate into new form.
6. Creating a vaccine can take months. First they need to do all the testing and analysis to ensure safety and that it works as planned. Then they need to grow lots of that virus in fertile chicken eggs, and the latter process takes weeks. After that, I assume it takes a few weeks to process the virus-rich chicken eggs into vaccine and distribute said vaccine. At any rate you can't just whip up a giant industrial sized vat of vaccine in a lab somewhere in a day.
7. Most people who get influenza recover. However, with pandemic flu, we're dealing with a large scale outbreak. This can overwhelm medical facilities to the point where the only medical care is that which family and friends can give victims.
   Complicating factors, one of the hallmarks of pandemic flu is that it strikes down healthy adults. For the very sick, there may be no ventilators, no antibiotics for secondary infections, no steroids, no IV fluids. At that point, it will be as if we've gone back a hundred years in time.
8. If the health care system is overwhelmed, some people will be just fine on their own, some will die regardless of what anyone does, and there will be a percentage who live or die based on the nursing care they receive from others. Knowing how to make oral rehydration salts, and keeping flu victims warm, dry, well fed and rested, may mean the difference between life and death.
9. Vaccinations for seasonal flu are still a good idea even if they won't treat pandemic flu. Two important points to consider are that (1) flu is flu and if you're deathly ill from regular flu and health care system has collapsed due to pandemic flu, you're still up a creek without a paddle even if it's not Captain Tripps The Death Flu. Regular flu kills too, particularly if you can't get modern medical care. And (2) if you're infected with both swine flu and season flu, the flu viruses can have virus sex in your cells and swap bits of genetic code and you could end up being the unwitting index case of Captain Tripps The Death Flu Round Two, with the love child of the two bugs spewing forth from your cells to start a whole new round of pandemic joy.
10. Yeah, everyone knows that the 1976 Swine Flu outbreak didn't amount to much. It fizzled after a month, and the vaccine made more people sick than the disease itself. However, the devastating pandemic of 1918 also had some swine genetics. They did a survey of antibodies of people who were born before 1918 a few years ago. 100% of them had antibodies indicating infection. Estimates for the number of people who got sick vary between 25% and a third of the world's population. Millions died.
    

Sources:

http://www.cdc.gov/flu/about/qa/disease.htm
http://www.pandemicflu.gov/plan/healthcare/influenzaguidance.html
http://www.pandemicflu.gov/faq/pandemicinfluenza/1070.html
http://uk.reuters.com/article/usTopNews/idUKTRE53P2KH20090426
http://www.cdc.gov/swineflu/guidance_homecare.htm?s_cid=tw_epr_61
http://www.umt.edu/curry/HealthTopics/cold-and-Flu/supportive-treatment-for-flu-colds.html
http://www.cidrap.umn.edu/cidrap/content/influenza/panflu/news/aug1908antibody.html
http://www.cidrap.umn.edu/cidrap/content/influenza/panflu/news/apr2209swine.html
http://www.cdc.gov/ncidod/eid/vol12no01/05-0979.htm