Yes, tried, failed, and it's a bitch.
I will give you the Nashville perspective. I'm sure it's similar in other music centers as well.
Large publishers will not generally accept unsolicited submissions. For you to get your stuff in the door you need to have an "in" somewhere. That's where networking comes in (at least here in Nashville). You start getting out in the songwriter community and making contacts, co-writing with others etc. One of them gets an "in" and brings some of your co-written stuff with you kind of get an "in" of your own.
There are also second tier publishers. Those with some success under their belts but who have not made it big time yet. These are the folks that do well by us newbies comparatively. They have smaller catelogue and your song is less likely to get buried in gigantic catalogue like the biggies have. These guys also tend to work harder for you if they believe in your work.
It also doesn't hurt to join a songwriters organization. There are a bunch of them out there. I belong to the NSAI since I am in Nashville and am mainly in to Country Music. They can give you good advice on how to submit songs. There are, after all, rules to this game and it's good to know them before you start shotgunning your stuff all over creation and pissing people off. One good book to find is called "The Songwriter's Market" (I think - I haven't looked at mine for awhile). This is published each year and has listings of publishers in all areas of the country. It's good resource.
I would suggest you start doing a little homework on how the system works in the area of music you are interested in. Start networking and collaborating with other songwriters.
I have had an offer of a one song publishing deal. I almost signed and was advised to hang on to my song. The publisher I almost signed with had a reputation of being a tad on the shady side and has not had any major successes. This is where the professional organization (NSAI) came to my rescue. Then on the other hand, if you have the best song in the world and never let it go to anyone, it will never make you any money. Confusing, I know

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Anyway, that was kind of a breif overview of what I know. If you have any more specific questions fire away. Someone around here will probably have an answer.
Good luck dude!!
