When you're at that point with your band where you're ready to record some new material, the discussion of how many songs you should record will soon follow. In my experience, most bands/artists seem to want to record all of the tunes they have on the table or as many as they can afford. They're excited about every song. Each song is very important to them, almost like it's one of their children.
And although I completely understand this kind of attachment (trust me, I've been there), the problem is that most bands/artists don't have the kind of budget that would be necessary to record ten or fifteen songs. Their budget is usually quite limited and in this case, you're spreading the attention and resources thin on all the songs on your list.
Many bands/artists want to record a full-length album because throughout history, that's what bands have done; they made records. And this can still be a good idea if you're planning on taking the DIY road and working your ass off to sell your album by touring extensively and setting up a brilliant marketing strategy. If you're recording your music in hopes that someone is going to discover you and take care of all the red tape for you, then it's probably not such a great idea.
When you record a full-length album and use it as your main calling card to submit to labels, publishers, managers and agents, etc., they're going to listen to the first 30 seconds of the first song and if that doesn't entice them to listen to more, they're going to throw it away and move on to the next submission. All that work, time, money and effort put into making your record and in most cases, only the first 30 seconds gets heard.
For this reason, I think it's better to put as much resource into a smaller number of songs. Even recording just one song can be a great way to go. Here's a few reasons why:
1. You don't get locked into a bad situation with a studio/producer for a huge project that is not living up to your expectations.
2. The amount of time you spend in the studio will be much, much less and subsequently, you'll see results more quickly. Results that you can share with music industry professionals and your fans to keep your buzz going strong. This is something you can do every month or every quarter and you will appear to be very consistent and hard working in your efforts.
3. The results will be of higher quality simply because you were able to put much more resource into the one song and because of this, it will be received more positively. Always leave your audience wanting more, don't make them wish you gave them less.
4. When a band records a full-length album, there's usually a consistency within the recording in that all the songs are a snapshot of where the band is musically and creatively at that time. Therefore there's not much growth from one song to the next. If you record one song every month, the growth in musicianship, songwriting ability and creativity will be much more significant. By the end of a year, you'll be so much closer to creating your 'sound' than if you were to record a whole album over a year.
Making an entire album is a huge undertaking! It can take a very long time because of scheduling conflicts among the band members and with the studio you're working at and because of this, it appears as though not much is going on from the perspective of your fans and industry pros. You can keep your audience tuned into what you're up to via youtube videos and so on and that's definitely a great thing to do, but I've seen this kind of thing go on and on for months or even years to the point where the fan base has lost interest and they've moved on. The buzz is dead.
I'm not saying don't make a record, I'm just suggesting that you think about exactly what that entails and if it's the most sensible move for you. Look ahead to what comes after the album has been recorded and manufactured and/or uploaded to the digital world. Make sure you have a plan of action that will make your efforts worthwhile.