Welcome to Inkscape development! There are so many different ways in which you can help. These are some starting points to help you find the best way you can contribute to Inkscape.
Inkscape can be made more widely accessible, by translating it to your language. We already have lots of translations, but new developments make maintaining translations a continual job.
To translate Inkscape, please see the launchpad translators instructions >here<, for help with translating the website, and for other documentation, please see this documentation >here<.
Inkscape is a large software project. Great documentation can help users get the most out of the software. Documentation can range from the wiki pages and website guides to wonderfully produced web videos that show users exactly how to use features and achieve results.
Please check out the Writing Documentation guide >here<. You can find information on how to edit various documentation as well as materials and graphics if you want to make videos.
Dealing with bugs is a critically important job. This could involve submitting a bug to the bugtracker, writing a patch that fixes a bug or testing to see if the patches have fixed the issue. This helps keep the administrative side of inkscape's development in good working order and improves the effectiveness of developers as they have access to better and more accurate information.
See the Bug Management guide which will show you how to use the bug tracker to manage bug reports from users. It is highly recommended that you read it if you want to help in this area.
Inkscape Extensions are written in Python can make Inkscape to do all sorts of cool things. If you've written an extension or want to learn how, you can start by following the Writing Extensions guide >here<.
Working on Inkscape's code base requires knowlege of C++ and Gtk development. Features developed by core developers make it into releases and really effect users directly.