In this article I'm going to cover what you need to check before you install SQL Server on your laptop or PC. I will assume you will use a personal laptop or PC and you are an administrator with permissions needed to install SQL Server.
The requirements will vary depending on which version of SQL Server you want to install and I will assume you want to install SQL Server 2014 which at this point in time is the latest version.
The information below is short version relevant to persona Laptop of Microsoft page Processor, Memory, and Operating System Requirements
I would say you neeed at least 2GB of memory if you want to run SQL Server on a personal laptop and 4GB+ if you want to use BI Stack (SSIS or SSAS Tabular in particular as they are memory based). For more info visit how to check memory size
Processor should be at least 2.0 GHz. For more info visit how to check processor speed
Operating system should be Windows 7, 8 or 8.1. If you run lower version (Vista, XP) than you should use lower version of SQL Server.
Before you make the installation
If you want to avoid issues during install I recommend to install ALL windows updates, including optional, restart PC and check for updates again and repeat until there no updates avialable.
That is basically it. If you want to read detailed requirements than please visit Microsoft page Hardware and Software Requirements for Installing SQL Server 2014
Next you have to decide on Version and Edition of SQL Server you want to download and install.