You would use ADO.NET to work with an Access database, just like you would any other. Assuming you're talking about an ACCDB data file, you would use the System.Data.OleDb provider and you will need the ACE OLE DB provider installed. That provider is installed automatically with Microsoft Office, or you can download and install it separately. It comes in 32-bit and 64-bit editions and your app will need to be built to with the same bitness. That also means that your end users will need the same edition of ACE, e.g. if you build your app to run in a 32-bit process (targeting x86 or targeting Any CPU and checking Prefer 32-bit) then no one with just 64-bit ACE installed will be able to use it.
Are you starting from scratch or have you already tried something that failed? If the latter, please ALWAY provide all the relevant information, so we don't spend time explaining things that you already know.