What will 'web services' do for us?

We are a small, mid range service company.  The services we provide could be categorized as facility management.  We are looking to impress a few of our larger clients that we provide services to.  One of the ways we would like to do it is with technology. Specifically, web-enabled technology.  My question is related to getting advice on how to do that in 2008 and I would appreciate ideas.  Here is the typical scenario, they send us requests for service either via email or telephone.  We track/manage and report on the requests in an access database.  When it is time to bill them for the services, we use our main business system which has a SQL Server backend and then we send them invoices either via EDI or paper copies, etc.
Based on that simple overview- how can we collaborate with them?  For instance, it would be great if we could provide them with some live data from our project management (access) application (i.e. project status, notes, updates, open issues, etc...).  I know very little about web services, but is a web service sort of a bridge?  
We have limited technological resources currently- but we are willing to get people trained in these technology areas so that we can have added value to our customers.
All suggestions appreciated!   Thanks