Hi Ahmadou,
On top of what Nagarajan has given, for implementation SAP have provided what's called Accelerated Implementation Program or AIP for short.
Some information can be found publicly here (SAP Business One Accelerated Implementation Program 2.0 - Business One - SCN Wiki)
The latest version can be found on the SAP Partner Edge website, authorized S-Number required.
Kind Regards,
Nick Lakasas