Download the ISO, extract it with 7-Zip or mount it in your VM and then run the setup, simple. Sure there is more to this but I will complete this later....
It is strongly recommended that you apply the latest Service Pack when doing an installation, unless you have some very good reasons. There are things called Cumulative Updates, which are like hot fixes, these should only be applied if you have the specific errors that are fixed, or if something like SharePoint depends on it and is documented in its requirements or installation documentation.
This is a great way of making life easy. So for example if you are doing several installs of SQL Server 2008 R2 for example, rather than keep applying Service Pack 2 every time you "slipstream" SP2 into the installation, which then means you just do the install and it gets SP2 from the word go. See the following links for more information:
When installing SQL Server into a cluster be extra careful when reading Hardware and Software Requirements for Installing SQL Server 2014. In addition you should carefully read Before Installing Failover Clustering which provides important information. In general most problems occur because people have not read the two articles referenced. Here follows some key things to do or consider before installing SQL Server into a cluster:
Description | Path | Size |
---|---|---|
Master, Model & MSDB Databases (Data & Logs) | R:\ | 10 GB |
Temp Database (Data & Logs) | R:\TempDB | 100 GB |
Database Files | R:\Data | 200 GB |
Transaction Files | R:\Log | 50 GB |
I also suggest naming your standby node 00, so that your first active node name ends 01. Whilst this seems odd at first, when you start adding more nodes it then makes perfect sense. I have seen cluster built with the first active node name ending 01 and the standby as 02 but this was only okay for a time! You might not think the cluster will be added to now or ever but it might be!