Hard drive is defective but runs. Need to replace, How and what to load on the hard drive?

First, I know enough to get me into trouble!

I have a 15R 5520 laptop running Win 7 Home Premium that I got in 2012.

The local computer shop has told me that my hard drive is defective but still runs.  They can replace and install a new hard drive for $80.  They have recommended a 500GB drive instead of the 750GB  that came with the laptop.  They say a 500 will last longer than a 750 in their experience.  I have only used 88GB at this point.  I had to pay $50 for the diagnostics but they will apply this to the $80 hard drive install if I do it in 30 days.

Once I get it back I will need to reload all the programs and files to operate.  I have the Win 7 disks so I should be able to install Win 7 alright.  It will have to download all the updates that are needed after I get connected to the web.

The question is what do I reload next? I will need to reload the wireless drivers first, I assume, so I can connect to the net without a USB cord. I would have to connect to the router with a cord at first to get those drivers.  Where do I get the drivers for the network and other cards?  In what order do I install the drivers and programs?

I can't afford a new laptop so I need to do this myself.

Any help and instructions will be greatly appreciated.  Let me know if you need additional info.