For the Firefox flash plug-in, if you are using 32 bit F10, you can create the symbolic link with this command:
enter root password
ln -s /usr/lib/flashplayer/libflashplayer.so /usr/lib/mozilla/plugins
If firefox was open when you did that, then close it and restart it.
When you type
in the url bar of a browser tab, it shows you which browser plug-ins are active. You can not change any settings from that page. If you successfully installed the flash plug-in for firefox, then you should see an entry titled "Shockwave Flash". You can also check your firefox plug-ins by simply clicking on Tools > Add-ons > Plugins from the firefox toolbar.