new SSD, how do I install Mountain Lion?

Doesn't have to be USB 3.0 (USB 2.0 enclosures are cheaper) - though if you can find one for a good price, go for it.

As for which software to use - I use SuperDuper (they have a free version), but many people here use CarbonCopyCloner (free if you use version 3.4.7 or earlier). Both are very straightforward and easy to use.

 

I'm going to need this info soon

 

If this is a "big" mac with more than one SATA port you can just plug the SSD into the other SATA port. If you are using a "small" mac with just one SATA port you can get a SATA to USB cable and plug the old drive into a USB port.

1. Shut down computer.
2. Plug the old HDD into the other SATA port or USB port.
3. Boot from old HDD by holding down the option key at boot.
5. Download cloning software.
5. Clone your current drive HDD to the SSD.
6. Reboot onto the SSD

 

"I've bought a new SSD, whats the best way to get it up and running? Should I encapsulate it into a USB 3.0 external case and clone whats now on my regular HD?"

Yes, that's EXACTLY the way you should do it.

You don't need to "encapsulate" the drive. You can get something like this:
http://www.amazon.com/Plugable-Dock...=2025&creative=165953&creativeASIN=B003UI62AG
Cheap, easy-to-use, will become a very useful peripheral to have close by when you're done with it.

You should use either CarbonCopyCloner or SuperDuper to "do the clone". I recommend CCC -- it can also clone the "recovery partition".
Note: You didn't say what version of the OS you're using. If you're using Mountain Lion, you need CCC version 3.5.2 (free download and free usage for 30 days). If you're using older software, you might be able to get away with using the still-free earlier version of CCC (3.4.7, available at http://www.bombich.com/download.html)

IMPORTANT:
Once you have created the initial clone, TEST BOOT IT before you do the drive swap.

To do that, do this:
- Restart
- As soon as you hear the startup sound, hold down the option key and KEEP HOLDING IT DOWN
- In a few moments the startup manager will appear
- Select the external (NEW) drive, and hit return
- The Mac should boot from the external drive
- When you get to the finder, go to "about this Mac" and be sure you've booted from the external (it will look exactly as does the internal)

If the test boot is good, and if everything looks ok, NOW it's time to actually do the drive swap.

After the drives are swapped out, you can continue to use the OLD drive to serve as your backup. Just do an "incremental cloned backup" periodically. You ALWAYS want to have a SECOND, fully-bootable clone of your internal drive close-at-hand. It will prove most useful in the future, when you have a "moment of extreme need". And you will have one of those one day. It's a "computing fact of life"...

 

I added a SSD to my Mac Pro and used Super Duper. It worked like a charm, much faster than Time Machine and easier to use. Next step is adding a second processor (I bought the quad core in 2008, and it is only now showing the effects of old age, though when I had a MacBook to compare it to, the old Pro still proved faster).