The Electoral Commission have launched a website outling the situation for this coming May's Local Government and the Scottish Parliamentary Elections.
There is an interesting section on how the single transferable vote system works and how to vote, obviously not who to vote for! I would encourage everyone to have a look at it as it is a really useful resource, it does not go into the boundaries and what they mean for you, but your local council should be able to provide this for you, I will personally be putting on a post outlining the changes for my constituents and maybe (if I can work out how to get it online) a graphic as well!
One of the sections on the site gives you a link to download a postal vote application form which because you have put in your postcode has the correct return information. If you are wanting to know more about postal vote applications please contact your local Councillor or your local Council, Renfrewshire Joint Valuation Board