Simviation is a place where flightsimmers can get scenery, planes, panels and lots more add ons for flightsims of a variety of types. This is my favorite site for add ons.
Flightsim is another site for flightsim addons. This site is free but you must sign up to get access.
Here's another site for flightsim addons.
This site has aircraft carrier add ons to put more carriers out there to land on. It even has an add on (cvn.zip) which will add carriers all over the world. This one is mostly FS98 but worth a look.
FSNav is, without a doubt, the best single add on you can have for FS. It will display a map of the world with all the airports on it so you can figure out which way to go. Check the site to see what I'm talking about....UPDATE: Well, sorry folks. FSNav is now shareware. (after all the nice things I said about it too, sheesh). Anyway, if ya still want to check it out.
Here is a well written and informative lesson on aerial navigation. Wish I could say I wrote it but twas not I that done the deed.
Ok, now that you have some planes to fly, learned how to navigate and stuff to navigate with, you need places to navigate to. Well, this is a good source for ideas on where to go. It has alot of routes to follow and links for more FS addons.
This is a link to the great and famous Moose123's site of FS fame.
This is dt676's site. A privileged peek into the mystery that is dt's world. Ya'll are so lucky. Enjoy.