Getting into Android development can be rewarding, but there's also a lot you need to learn. If you have some experience with code but want to transition to becoming a developer, Udacity has a year-long curriculum of material straight from Google that can get you started.
The curriculum is part of Udacity's Nanodegree program. The Nanodegree program is designed so that students have a portfolio of projects to show employers by the end of the course. Since the programs are developed with help from the industry, it's a pretty safe bet that what you're going to create is what potential employers want.
The Android development Nanodegree program was just announced at Google I/O and costs $200/month for a 12 month course. Udemy is also offering to refund 50% of the tuition costs if you graduate within one year of the time you enrol. The costs might be a bit high for hobbyists, but if you're looking to get serious about developing as a job, it's hard to beat the price for an education straight from Google.
Android Developer Nanodegree [Udacity]