Bards are a great support soul, their buffs provide great utility to the group and their AOE 'trickle' healing can help on tough boss fights and give your group a definite edge.
There are issues with the soul at the moment around its comparative power against Chloros, but that's for another discussion.
People seem to struggle with the concept of the Bard especially when they haven't utilized it from the start of the leveling process. There are 5 main concepts to this soul
1. Motifs - your bread and butter 30 seconds (talented) buffs
2. Anthems - Typical Auras.
3. Fanfares - 60 minute group buffs.
4. Codas - Finishers.
5. Cadence - Main healing ability.
How to play a FULL (dedicated support role) Bard.
1. Keep your Motifs up on the group, be careful and do them before your tank starts to pull or you can get buff aggro.
2. Cadence Cadence Cadence. Use cadence to provide your group with trickle heals. Power Cord and Riff can be used when on the run (Second boss of FLH) to build combo points and pop off a finisher to make up for lost Cadence time.
3. Coda of Restoration at 5 combo points. Now you can get tricky if your group doesn't need healing, and pop off the increased physical and increased magical damage finishers if need be.
4. Your 'oh-shhhiii' button is Virtuoso. Your group needs 15 seconds of Coda of Restoration spam because your healer is shut down? POP IT. Make sure that you have 5 combo points on the enemy however a quick Riff usually does the job. Don't get caught popping it and having no combo points up.
So in summary a fight would be.
Motifs > Pull > Cadence > Cadence > Coda of ..... > Cadence > Cadence > Coda of.... > Motifs > ......
^ I'm not saying use that as a rotation but hopefully it gives you an understanding of the class' playstyle.
Points to remember.
1. Keep your buffs up.
2. Spam Cadence.
3. Use Coda of Restoration.
Now obviously Bard can be paired with a myriad of different souls. Ranger/Bard works quite well you get some nice DPS from ranger with the bonuses of the motifs and the healing finisher. Bard/NB/Assassin work well due to all the damage boosting talents. Remember your damage is your healing, so don't go silly and buy spellpower runes and start running around in robes.
Bare-bones Bard Spec:
(Resonance is also a good talent but is not required a 5% increase to strength isn't really that amazing.)
Go Bard or Go Home!