If you think killing an elk with a rifle is a slam dunk, then you're sadly mistaken. The average here in CO. is some where around 20% of rifle hunters get an elk! Getting an elk is work, no matter the choice of weapon you choose.
If you have no one to go with, and have no idea how to hunt them, where to hunt them, how to get them off the mountain, then I'd suggest an outfitter. Not cheap, but you'll learn alot, BUT still no gaurantee off success!
Do alot of research. I love the aspect of bugling elk that comes with bow hunting. You rarely run into crowds during archery season. The weather is more predicatable in Sept. If you love to bow hunt, then try to find a group of bowhunters that have been several times, and try to get in with them and let them show you the ropes. It's a blast, and I hope you get the chance to experience elk hunting.
Colorado has the most elk, and probably the easiest tags to aquire. Still some over the counter tags, and there are areas that have good hunting without preference points.