UUA.org has a growing general online resource library for leaders. By playing with a variety of search terms, you will find good material. Be persistent. For example, while searches on “publicity,” and “welcome” yielded little, a search on “membership” yield a variety of good things.
On the broader subject of resources, any UU congregation emerging today will find itself in an amazingly fortunate time. The Web has become an amazing source of free, downloadable material. A little dexterity in searching will turn up a wealth of worship resources including complete services and sermons from other congregations (ask and give credit). Increasingly, emerging congregations make use of sermons (either written or pod-cast) posted on the websites of established congregations.
Historically, one of the best resources for emerging congregations has been the Church of the Larger Fellowship. Founded to serve UUs who are not near UU congregations, the CLF has many resources that might be useful for emerging congregations. The bulk of these are only available by subscription ($129.00 per year) or by joining. A sampling of materials is available for free including a basic online introduction to UUism class. Their Religious Education materials are particularly strong for very small groups and for support of parents providing education to their children.
In Spirit Books (The UUA online bookstore) has a wealth of very good books and pamphlets.
Recently the UUA has been producing, and distributing free or at nominal cost CDs and DVDs on lots of useful topics (Contact your district office and you may well be able to get some of these free).