I blatantly stole the answer from one of the comments to http://www.webupd8.org/2014/04/fix-lubuntu-1404-network-manager.html as Adz linked to and Eric Carvalho suggested be included in an actual answer. So, now we have the answer here in AskUbuntu. This is what I did.
This fix does not work for everybody... if that's the case for you, too.. then try this: go to menu >Preferences > Default applications for LXSession, select the autostart tab and scroll to find Network. Uncheck it and recheck it, then go to your home folder and press ctrl+h to show hidden files and folders, go to .config/autostart, there you will find a Network.desktop file right click on it and select Leafpad, it is likely that under NotShowIn section it includes LXDE just delete it, save the file and exit, then log out and login again this will fix the issue.
For those that came looking for the actual answer on that website, here it is.
Lubuntu 14.04: fix 1
To fix the Network Manager not showing up on the panel issue, from the Lubuntu menu select Preferences > Default applications for LXSession, then click on the Autostart tab and under "Manual autostarted applications" type "nm-applet", then click the "+ Add" button on the left:
Now log out, log back in and you should see the Network Manager icon on the panel:
fix somewhat via lffl.org
Lubuntu 14.04 / Xubuntu 14.04: fix 2
If the above solution didn't work for you in Lubuntu 14.04 or if you're using Xubuntu 14.04 and you're having this issue, here's another solution. Basically, the solution below is for those who must run "nm-applet" as root to get it to show up in the pane - we'll be using dbus-launch to launch nm-applet at startup.
To get the Network Manager applet to work properly in either Lubuntu 14.04 or Xubuntu 14.04, run the following command:
sudo sed -i 's/Exec=nm-applet/Exec=dbus-launch nm-applet/' /etc/xdg/autostart/nm-applet.desktop
The command above replaces "nm-applet" with "dbus-launch nm-applet" in the nm-applet autostart desktop file.
Ok, I also followed the advice from here:
What you need to do is edit /etc/xdg/autostart/nm-applet.desktop with your favorite text editor. I like nano, so I ran the following from the terminal:
sudo nano /etc/xdg/autostart/nm-applet.desktop
Go down to the Exec line and change the entry from nm-applet to dbus-launch nm-applet. Save the file and reboot!