Client/customer data maintaince

I am going to start a new business,i.e supply of weighing machines to different small and medium scale industries? .Iam having experience of eight years.I need a software that should maintain my client [login to view URL] example,clients requirement on future date with all details about the contract,i? will feed the data on my PC and the software should remind me on the same date about the delivery and it should automatically intimate the client about the same though there mail [login to view URL] software should maintain all the detailed information about the cliient like their mail id ,contact no,adress and all other information about the [login to view URL] software? should remind me and client about the contract in a proper [login to view URL] software should be user friendly.