I use a drip irrigation system that I bought from an online retailer called dripdepot. I installed it last spring, and it has worked great so far. The start-up cost is a bit pricy, but in the long run it has been worth it for me in terms of time-savings. The main reason I chose that company was for the shutoff valves they include in their kits that allow me to water only certain beds. I couldn't find any of those valves at our local big-box retailer and found it difficult to piece together what I needed without getting a kit. I have had concerns about seed germination using this system because the surface does not appear to be uniformly damp (I use 6" spacing), but so far everything has germinated well despite the dry spots on the surface.

With that being said, I have heard good things from people using other methods such as soaker hoses. Ultimately I think a lot of it is also a matter of personal preference.

I made the system in the link this year and couldn't be happier. It is a PVC grid/watering system. Makes watering much easier and I like that it's removable. A bit of work initially, but after that you're home free.

Here is a link that might be useful: PVC watering grid

kaptainkr - very cool watering grid! in a raised bed, do you bury the watering grid under ground or do you let it sit on top of the soil?