Hello Everyone,
i have been working for the last 2 decades with Microsoft windows clients and servers, but with the new financial struggles that Small Businesses are facing, i am trying to shift to SME 7.5 and up servers for my clients.
the problem is that i have zero knowledge in Linux world, all my clients use MS applications and OS and to be honest i am scared to take that path, but on the other hand it is too promising as an investment for me and my clients considering the very low cost for owning, maintaining operating and or upgrading a server of that kind, with all the benefits that exceed by far those off even the best MS servers.
all my clients are between 5 and 20 users, all using MS products and applications, 80% of them are architects and or graphic designers, which means heavy processing and RAM usage, plus the normal file and print sharing, adding some proxy setup and email.
below are few questions that i would like help with them , and they will be like a small study for me to be able to decide if should i ever choose to start implementing SME instead of MS Servers for my clients.
1- is this a good server to start with, knowing that it will only be for my own learning usage?
Intel CORE2 processor with around 4GB RAM, and 2 x 1GB hard disks with raid (or mirrored).
2- what should i consider if i want to start replacing MS servers with SME ?
3- depending on the brief explanation of the caliber if my clients, what server hardware shall i go with ?
4- last but not least what is the best way to go this path, i know everyone has his own way of treating things, but few suggestions from the experienced in here will really make my life easier

thank you all for reading this and contributing in helping me choose whether or not to take this new path in my career.
Francois