Healing can be a lot of fun. My Guild Leader is a tank and he once told me that to be a "better than average" tank you need to have the mindset for it, I do not have that mindset for tanking, but I do for Healing. If you are interested in healing as a priest it really depends on which type of healing you are looking for. Disc is great on some fights in ICC if you are looking to raid the new content (once you get some gear) and Holy is more of a raid healing spec.
To start I suggest playing as Disc, it isn't because its "easier" but because 1) its more mana efficient and 2) you will find it easier to keep the tank alive while in heroics.
As for gear, you get what you can get at first if you are building a healing set from scratch. Now the 4 set T10 bonus is worth it for disc priests, so that is a goal you can strive for.
This is my Holy spec if you are still more interested in Holy:
http://www.wowarmory.com/character-s...ywall&cn=Provi
This is my Guild Leaders Disc spec (he insists on not using FH and gets the job done rather efficiently):
http://www.wowarmory.com/character-s...all&cn=Betelle
Some general guidelines for healing: if you aren't having fun it probably isn't for you, don't get too frustrated when you start if people start dying, it happens and if they get irritated listen to what they have to say (if its just ranting about how they let ya die, then thats what the ignore list is for), and try talk to a guildie in game who heals - this has proved helpful for me time and again
On a side note: Holy is prone to going OOM more so than Disc, however if you manage your skills and GCDs correctly you shouldn't have too much trouble with mana
Good luck!