I have installed a second hard drive, a solid state drive (SSD), in my Mac Mini recently using the iFixit dual hard drive kit and the corresponding installation guide. This was all quite straightforward, but I can’t say the same for getting OS X Lion installed on the SSD.
I hoped it would be quick and easy to boot to the recovery partition on my existing Lion installation and install Lion on the new SSD. To boot the recovery partition, restart and hold down ⌘R. The recovery partition includes a “Reinstall Mac OS X” option which usually downloads several gigabytes of installation data from Apple and reinstalls the operating system. I went through this process, installing to the newly formatted SSD, about six times. Each time it failed saying that it couldn’t download the additional installation files necessary and that I should check my internet connection.
Finally, I decided to follow these instructions to trick the installer in a particular way to allow me to store the downloaded installation files and actually create a bootable USB stick from which to carry out the installation.