A good many RPGs assume one of two things: The PCs have known each other for a long time and have been travelling together for almost as long, or the PCs just decide to adventure together on a permanent basis after coming together for a single mission.
A good way to get the PCs to stick together is to give them a patron to work for. In Dragon Age: Blood in Fereldan, the PCs will run into Bann Nicola Baranti but more on her part in this set-up later.

The first adventure you should consider running is ‘An Arl’s Ransom’ which can be found in the free PDF Quick Start Guide: http://grfiles.game-host.org/dragon_age_rpg/DragonAgeRPGQuickstartGuide.pdf
We moved on to “The Dalish Curse” next.
This sets up the PCs to at least arrive in Denerim where you can run a scaled down version of ‘A Fragile Web’ up to the point where the Party deal with the Chantry of the Stilled Tongue, as it is here the PCs meet Bann Nicola who proceeds to offer the Party a position in her household as representatives, with the Bann acting as their sponsor or patron. At this point you can feel free to run the remaining adventures as you see fit to match your group’s Levels in game. From there, you can run the adventures by their recommended level order. See the recent Oracle post: https://dragonageoracle.wordpress.com/2014/07/12/welcome-to-dragon-age-explore-the-adventures/ containing a list of all the adventures, both Official and fan made. After all of that, you can return to and finish ‘A Fragile Web’ hopefully with your players being Level 5 if not bordering on 6.

(Editorial Note: Thanks Lory, and I would like to add as I GM’d this campaign, that this plan serves to build a proper relationship up between the Bann and the party, rather than it simply being over and done with in one mission. This makes the twist connected to her all the more meaningful and shocking to the players!
Also bear in mind that the new collected edition book (all three sets rules together) will contain a new and different mission to the Dalish Curse, so this will factor into your tier 1 plans mentioned above as it becomes available. The hope is that Green Ronin will also make this adventure available separately, at the very least as a PDF release – but I know for a fact that they are making internal enquiries about doing that very thing.)