There are several blogs that describe the steps necessary to install SQL Server 2012. My two favorites are Step by Step: Installing SQL Server 2012 RC 0 written by blakhani and How to install SQL Server 2012 written by Alberto Morillo.
But installing SQL Server 2012 can be a little confusing. For example, when installing SSAS (SQL Server Analysis Services), when you get to the Analysis Services Configuration step, you need to choos either Multidimensional and Data Mining Mode or Tabular Mode. You can only pick one. What you should know is that if you want them both installed, pick one, then after its successful installation, install SQL Server 2012 again, but the second time, when you get to the Instance Configuration step, you need to select Named Instance and install it as a separate instance. Then, during the second installation, when you get to the Analysis Services Configuration step, select the other option.
The other issue that can sometimes be confusing is the installation of SSDT (SQL Server Data Tools.) SSDT is the replacement for BIDS (Business Intelligence Development Studio.) It is a subset of Visual Studio 2010 and it has a set of Business Intelligence tools. But, depending on how you install SQL Server 2012, you may or may not install SSDT at the same time that the other components of SQL Server 2012 are installed. If Visual Studio 2010 is not installed at the time you install SQL Server 2012 and, if you choose "SQL Server Data Tools" on the Feature Selection page when installing SQL Server 2012, a portion of the SSDT tools will be installed. Missing are the tools for building SQL Server database solutions/projects. To install the missing tools, go to Install SQL Server Data Tools. Go to the paragraph titled "To install SSDT while creating a Visual Studio 2010 project:" and follow those instructions.
If you installed Visual Studio 2010 before installing SQL Server 2012, ensure you have SP1 installed, then install SQL Server 2012.
