Warning 1 The referenced assembly “Microsoft.SharePoint, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c, processorArchitecture=MSIL” could not be resolved because it has a dependency on “System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a” which is not in the currently targeted framework “.NETFramework,Version=v4.0,Profile=Client”. Please remove references to assemblies not in the targeted framework or consider retargeting your project

Solution Here for this issue: http://mycodelog.com/2010/03/25/vssp2010/

Resolution

SharePoint 2010 is built on top of .Net Framework 3.5. So make sure you have it as your targeted framework in VS. Go to project properties and change the target framework to “.Net Framework 3.5″.

Run Issue

The Web application at <url> could not be found. Verify that you have typed the URL correctly. If the URL should be serving existing content, the system administrator may need to add a new request URL mapping to the intended application.

Resolution

You have an x64 version of SharePoint Server installed, but VS 2010 is building your code as x86. So go to project properties \ Build and change platform target from x86 to x64.