I've been developing in .NET now for about 3 years. I love the visual studio IDE and sadly I won't be able to use it anymore.
Could someone save me hours of searching the web and reading reviews, and suggest the 'standard' or most popular IDE/Text editor for linux that will get me up and running quickly?
My main goals here are web development backed with Python.
First off, if you want to do web with Python, the Django framework seems like the best choice.
From some quick Googling, the best IDE for Django would be NetBeans with a plugin.
Good luck on learning 'nix development, then!
Check out this article which, among other things, points to this previous SO question.
I really like gedit and a terminal. You'll more than likely need to make a few tweaks and maybe install a plugin or two. gedit also has a Python console window plugin if you like that kind of integration. (Edit -> Preferences -> Plugins, then enable the bottom pane with View -> Bottom Pane)
If you're new to Ubuntu I'd still recommend trying a few different tools before you get settled. The impression I get is that text editors are more commonplace than full blown IDEs on Linux. I tried a few IDEs on Ubuntu and it just didn't seem right - gedit is lightweight and I actually enjoy using it more than Textmate on OS X.
If you are willing to pay Wing IDE (http://www.wingware.com/) is the best (IMO) They have trial versions and a basic version free (https://wingware.com/wing101)
Consider Wing IDE -- IMHO the best commercial IDE for Python, it does support Django if that's what you want (as, apparently, do 80% of Python-based websites; personally, I prefer werkzeug and the like, but maybe that's partly because my "web apps" tend to be more like "web services", with most all the UI/views parts done in HTML/CSS/Dojo;-).
Me, I use Vim (usually in the gvim incarnation) as my "Python IDE" (and I've seen Emacs-using colleagues do at-least-equivalent wizardry, but I just can't get used to Emacs myself!-)... but I have to admit that a Wing IDE expect, particularly if faced with a thorny debug scenario, can do circles around me (and even around the Emacsers). ((So why haven't I made the effort to switch? Maybe because, thanks to fanatical testing, I now face thorny debug scenarios too rarely to make me an expert in any new tool!-)) ((Or maybe because my fingers, having learned vi 30+ years ago, would HATE me if I switched to ANYTHING else;-)).
If you've been using visual studio, then I'd guess that mono develop would be the closest thing. As far as I know, its the best attempt around to be a linux version of visual studio. A quick Google search gives several results for python plugins for mono develop.