Like anything else, it takes time to get to a point where it is enjoyable. Also, improvement comes in stages (you'll level off for a long time until you make the jump to the next level), so it's easy to feel disheartened from time to time.
Keyboards are probably the best introduction: can see the visual relationship between the notes making up a chord (which u can use later for guitar and any other instrument), isn't physically painful like the strings on a guitar/violin are in the beginning. You can get a basic one, which is all you really need, for a very reasonable price; they are lightweight, so it's not the burden that a piano would be; and my favorite is that you can used headphones, so that no matter how bad you are, don't have to feel embarrassed disturbing your neighbors/roommates/loved ones when you practice.
1) Buy a very simple introduction book (really basic, step by step) start with the basics.
Decide on a specific, regular time that you want to practice. (I would come home from work, shower and change. Then sit down for 30 min. before dinner, Mon-Fri. Of course I could fiddle with it a bit more later as well, but at least 'I got my 30 min in today, anything else is just for fun.')
2) Also get a very easy book of some simple songs. Once you can play a song, and especially after you can play about 4 songs, you have something that sounds nice and makes you feel good about yourself. Just something simple to give you a first goal.
3) Once you get there, you can decide to get more books, or continue what you're doing, or 'I've been really getting into this enough that I think I want to find a teacher and take some lessons...' Just depending on how you feel then.