Im considering getting one of these servers for home but just wanted to run a few things by you experts first:
1. I currently run an accountancy business from home and everything is stored on a Win7 laptop which works fine currently and I back up the documents via always sync to a NAS daily (albeit I have to do it manually) however I worry that if something went wrong then its possibly a lot of down time.
Would WHS2011 on N40L Microserver be a more suitable option for me to backup everything to there and then look at an offsite backup solution on top of that? Someone recommended me to have a look at Carbonite as a cloud based solution? I dont have huge amounts of data as they are mainly word, excel etc but probably looking at 5GB or so.
WHS is great at acting as a centralised shared storage device and backup device for up to 10 PC's. I also use cloud storage for my most precious docs but instead of carbonite I use Crashplan which for me works out at £3.00 or so a month for UNLIMITED data storage.
I am looking at office premises in the next few months so it might even be a possibilty to look at one server for home and one for the office and RDP (or similar) into the office server.
You can do that. WHS comes with a neat remote access website for accessing files and folders and media over the internet. You can also install a remote access tool like LogMeIn free edition which is better than RDP in my opinion, for accessing the servers desktop over the internet.
2) I have Sage Act 2010 which runs on Mysql I believe, which never backs up properly using always sync and instead I have to go into Act and create a backup which can then be synced. Would using WHS allow everything to be backed up automatically?
No. It doesn't have a database aware agent as such. It's primary usage is disc image backups using VSS technology.
3) Power useage, what sort of usage would I expect from having the server on 24/7? Currently I only have the laptop when I need it and in hibernation mode when not in use.
Not sure to be honest. Not measures it, but its on 24/7 for me.
4) Emails, being the only "employee" I just use IMAP for my emails and Google calendar for my diary which syncs between my laptop, desktop, iphone and Ipad. Will there be any problems using this method under WHS?
Yes this will work fine (although I struggle to see why you'd want to!). Install whatever imap client you want on the server.
5) I have recently just bought an Apple TV2 and installed xbmc on it. I assume it will be fine to store all the media on the the WHS and access it from the ATV2?
Yes, streaming is very good. It acts as a DLNA server for anything that can see it.
I think is everything but if you have any further advice then please fire away. My main goals is to have a solution that "just works" and doesnt need much/any tweaking and is backed up properly to ensure as little to no downtime as possible should there be any problems.
This is the beauty of WHS. It will back up whatever machines are on - every day between times you set automagically

And with Crashplan anything inside of folders/drives you specify will get automatically uploaded to the web either immediately or on a schedule you dictate.
Works great for my small business
Thanks, Mark