Follow below steps:
Open visual Studio 2010, Click on File -> New project. Then from the New Project dialog box, Select Visual C# -> SharePoint -> 2010.
Then from the list of SharePoint 2010 project templates select Empty SharePoint Project. Give a name and make sure .net Framework 3.5 is selected as shown in the figure below:
In the next step Give a local site for debugging and Select Deploy as farm solution and click on Finish as shown in the figure below:
Now Right click on the project -> Add -> New Item
Then from the list of installed templates Select Visual Web Part
, Give a name and click on Add as shown in the figure below:
Now open the .ascx file and add the following script:
After that deploy the web part. The jQuery will be available to those pages where you will add the web part.