Hi Erkur1,
There are many good tools for online project management, tackling many issues such as: project management, task tracking, issue tracking and more. Some also provide a mutual workspace for sharing/collaborating documents. Depending on your needs (do you need it mainly for you/you+1? for a small team? for an enterprise), the pricing varies, but with some of the tools - if you're going to use it in a limited way (i.e. small number of users, limited features) you can start with a free account (not only for trial. Raert.
Some prominent players are:
1. Basecamp (http://www.basecamphq.com/) (you can do a 2 people project for free)
2. SocialText (for collaboration environment using Wikis)
3. Zoho (for document collaboration. you can start free)
There are MANY other players. You can find some deeper discussion of these and many other solutions here: http://webworkerdaily.com/2007/04/07/alternatives-to-basecamp-for-project-management/
and here:
http://www.techsoup.org/learningcenter/software/page7648.cfm?rss=1
Hope this helps,
y.