In reply to this tweet:

ebd35
Mary Farmer

@johnjohnston hi. When I've mentioned on here about starting a blog with class your name was mentioned and something to do with hosting???
Wed Oct 27 09:34:34 +0000 2010 from Twitter for iPhone captured: Wed, 27 Oct 10 18:12:23 +0100

Here is what I know about hosting.

For several years I ran blogs at Sandaig Primary. The Web site  there was hosted by http://www.blacknight.co.uk/ who offered free hosting for primary schools. To use their hosting for blogging with wordpress you do need to pay for a database. Blacknight are very responsive and helpful. Originally I used another blogging software that did not need a database.

Update:

blacknightsw
Stephen Thirlwell

@johnjohnston @ebd35 We do indeed provide free hosting for schools though databases are chargeable there is a 10% discount off pricing.
Wed Oct 27 18:27:35 +0000 2010 from Osfoora for iPhone captured: Wed, 27 Oct 10 22:28:57 +0100

and

blacknightsw
Stephen Thirlwell

@johnjohnston @ebd35 We are looking at providing a free database which will be subsidised by advertising. Email for full info if reqd :)
Wed Oct 27 18:30:13 +0000 2010 from Osfoora for iPhone captured: Wed, 27 Oct 10 22:30:52 +0100

To run a blog on a hosting service you need to do a wee bit of work, installing Wordpress and setting it up. You need to keep an eye out for security updates and be able to use FTP software and follow instructions. A wee bit of knowledge about how web stuff, html ect might help.

Alternatively you can use a blogging service. for many years edublogs.org has provide a service for free. They now charge but provide free with advert blogs.

In the UK John Sutton (HGJohn) provides blogs for schools as does John McLear (johnmclear) I've not used either of their services but heard good things about both. 

In Scotland we are luck enough to have wordpress blogs supplied by Glow, this is in its infancy but is looking very good so far.