My background(If it's too long, just skip it please ; ) ): I am Java programmer(because of demand): mostly teacher for other students, worked on few thesis for others, but during my journey I discovered that .NET and Microsoft's tools are on at least two levels higher than Java and its tools so I want to learn more about them. I programmed little bit on Windows Phone(NFC Tags, TCP Clients, guitar tuner using internal microphone, simple RSS), used WPF, integrated WPF with Windows Forms, Apple Bonjour(.NET), I have expierience with IP cameras and with unusal problems, I learn Android, but I don't like it at all.

Problem: I was asked by my friend to create CRM for small new company. There will maximum 20 workers in the company working at computers in few cities in the country(Poland). They just want to store contracts with the clients and client's data. I am not sure what exacly they do but probably sell apartments so there will be at most few thousands of contracts to store in far future.

Now I am totally new to CRM but I want to learn. I have few questions:

1. Should the data be stored on a server in the company's building running 24/7 or cloud. If cloud which one?

2. Should I use ASPX or WPF. I read one topic about it but as far as I know aspx sites can be viewed from every device with internet browser: tablets, phones(Android, WP, iOS) and computers at the same time-> so the job is done once and for all(Am I right?), I don't know nothing about aspx. Can WPF be also used in manner that does not need to port it for other platforms?