Well, I will try to answer, even if officially I am learning Bosnian and your question is about Crotian... you will agree it is almost the same language.
I have a bosnian friend who is leaving in my village. She opened me up to bosnian songs (especially Dino Merlin) and I really loved the sonority of this language. For me, it was between russian and italian, even if I don't speak those two languages.
She thought it would be easy to me to learn bosnian, as she found french really difficult to her. But when I asked her to explain me each time I didn't understand something in bosnian, she realized it wasn't as easy. For french people (and perhaps for english people too), I think the most difficult point is the declensions.
The first two months, it was really difficult to me to translate something, even a short text, because I didn't know about declensions and conjugations, so I could not find the words in a dictionnary. It was really getting on my nerves! My first dictionnary was also a serbian one, and as you know it, there is some differences in the way to write some words (the "ij" which is added sometimes).
Now, I learn it for about four months, and I am more comfortable with it. I can translate a text with a good dictionnary, even if it takes me a lot of time. To write in bosnian takes more time, and I make a lot of errors, that is why I answer you in english
.
I found some basic ressources, generally in croatian, on several websites. I also exchange by mail with some bosnian people. And for the pronunciation, I will test it with my friend, when she will be back from her holidays in Bosnia.
Here is the way I learn Croatian/Bosnian.