DP, the working link on the wiki is to v1.00, rather than v1.01... is that a concern or is one as good as the other?
ETA that manually changing the link address from '...DragonAgeToolset1.00Setup...' to ',,,DragonAgeToolset1.01Setup...' allows me to download the preferred version so just ignore my silly question please and thank you. 
The CDN link was pointing to the wrong version. I've fixed that.
Which of these files should i download? this toolset is really confusing.
Alas that page is simply a repository of links to various resources on both the old BioWare Social Network and their new CDN so I appreciate it doesn't make much sense to a newcomer!
The only file you absolutely need is the Toolset. Ideally you want v1.01.
If you want to make your own levels (rather than reusing the ones BioWare created) then you'll need the Lightmapper script and a particular version of Python which we don't list on that page (see this section for details). You can install it if/when you decide to dabble in that dark art!
The entry under Design Resources was something I believe we needed for populating empty database. It's a builder-to-builder file containing all the core and single player (design) resources. It is not something we typically require any more unless, for example, you wanted to do a full manual database install (in contrast to the automated process or restoring from backup).
The remaining files under Art Resources are original BioWare resource files which can provide you with a head start if you want to start modifying the underlying art resources rather than just reusing them. They also be a handy learning tool because you can see what settings, etc. BioWare used to get a particular effect, etc.
That link worked. However, after i now installed it- it won't connect to the database instead!.
What version of Windows are you installing on? Did you get any error messages during installation? Do you know SQL Server installed and if it is running?
Also it can be a bit daunting but you can try the Database Troubleshooting Guide!