Is it worth a back-end developer's time to get into web-design and HTML/CSS
gommm: Like a lot of people here said, I think it's important for you to learn html/css. At least enough to be able to do simple websites (or modify designs that you outsourced to integrate them in your website.)For css try to use and understand a framework like blueprint or better even compass which is a meta-framework ported on sass (sass is to css what haml is to html). It will save you a lot of time by not having to deal so much with browser inconsistencies).On the javascript side, read the book "Javascript the good parts" from Douglas Crockford, watch his videos and then play with jquery (it's very sweet and simple to use).One last recommendation on the front end is to read Steve Souders "High performance websites". It's a quick easy read and highlights a lot of important considerations for the front end performance (like this you'll know for example that it's a good idea to ask designer to slice images that they use as background in the css file)...It doesn't mean that you need to do everything by yourself (I hate doing css for example) but having a thorough understanding will help you chose the right web designer to work with and make sure that you both speak the same language.