Photos: The Stars Ring in 2010
Colbie Caillat performs during Dick Clark's New Year's Rockin' Eve With Ryan Seacrest 2010 at Aria Resort & Casino at the City Center in Las Vegas, Nevada.

Love was all Colbie Caillat needed to inspire her third album, "All Of You," which comes out July 12.

While touring to promote 2009's chart-topping "Breakthrough," Caillat began a relationship with her guitarist and musical director Justin Young, which she tells Billboard.com was "a surprise to both of us. He was the guy who warms me up and talks with the band, so we had to work together more than we ever had. And all of a sudden I noticed I would change my outfit a few times before I would rehearse with him, and I would get butterflies when he would walk on the tour bus or when he'd talk to me or anything like that. We eventually talked about it, and then we started dating."

The two now live together in Los Angeles and recently adopted a puppy who will go on tour with them. But Caillat says she and Young find that their professional association only complements their personal relationship.

"We feel very lucky that we get to go on tour with each other rather than other people who have to leave their significant others at home," she explains. "It's really special. It's like having your best friend everywhere with you. Other people are like, 'How do you do it? I'd want a break' and whatever. I guess we just have that kind of bond. We actually enjoy doing it."

Colbie Caillat Taps Common, Opens 'New Chapter' with 'All Of You' Album

Caillat acknowledges that her relationship with Young inspired many of the 12 songs on "All Of You" (some of which he co-wrote), and she points out that they're not all moon-eyed and happy.

"When I was writing I wasn't going through heartache," she notes. "I was going through being in love, but there were times where we were having little rough areas in the relationship and trying to figure them out and not give up -- which is what I used to do in relationships. So I think maybe just the older I've become, and writing with amazing writers, I've learned about how to write from a different perspective."

But the first single, "I Do," does not mean what the title might suggest. "Everyone does think it is about me getting married," Caillat, who wrote the song with Toby Gad, says with a laugh. "I got texts. I keep getting messages, 'Did I miss something? Are you engaged?' (The song) is about being in love and taking your relationship to the next level, but if people want to use it as their wedding songs or think it is about marriage then they can go right ahead because that is what songs are for -- to allow people to have and be what they want them to be what they want them to mean for them."

Caillat's other collaborators on "All Of You" include Ryan Tedder (who co-wrote the single "Brighter Than the Sun"), Rick Nowels, longtime friend Jason Reeves and her father, veteran producer and engineer Ken Caillat. And Caillat -- who also appears on Dave Stewart's new album, "The Blackbird Diaries" -- acknowledges the pressures of expectations after "Breakthrough" debuted at No. 1 on the Billboard 200.

"There's always that," she says. "There are so many people that put so much hard work into this record, and I would feel bad if it didn't do well. I'd feel like everyone got let down or something like that. But, honestly, I know that they are amazing songs, they are beautiful and I can't take the credit for it because I did it with a bunch of other people. I'm really proud of all of our work, and I honestly think that my fans and new fans are going to like it."

Caillat has a short run of dates planned for early July -- including a performance on "All Of You's" release date at New York City's Canal Room -- and is planning a more extensive tour for August. "We are actually working on that right now," she says. "We have a new band, and we're working on a stage production. We're trying to make it really fun and kind of like an outdoors back yard. We want it to feel like people are in their house, watching a music artist perform in their back yard and super chilled-out. We're also going to have different set lists so that we'll be able to keep all the songs out there for the fans to hear and so all of the shows are new to us and we'll be excited to play each one."