There have been a lot of complaints about Siteground on the forum so I personaly don’t and wouldn’t use them to host CS-Cart. I use CyberLNC for my hosting and couldn’t be happier. CyberLNC’s site is: http://www.cyberlnc.com
As for installation, everything is kind of straight forward if you have a good host and at least a little knowlege. When you sign up with a host they should give you the information you need to install CS-Cart. All you really need is your ftp information to upload the cart and your database information like username and password. The only thing that might be at all difficult is to make sure your permissions are right on your directories.
If you need any help installing CS-Cart just look through the forums and I am sure your questions will be answered.
By the way CS-Cart is a great choice if you are looking for a shopping cart system and now with 2.0 comming out soon there will be a ton of new features that cost a lot extra with other carts.
Brandon