I've used various tools like Sparx EA for the last 30 years in my profession. I've used Sparx EA for about 12 years now which I've used for the purposes of enterprise architecture, solution architecture, software architecture and engineering. Its probably the best value for money and feature rich tool on the market place today. The tool provides all the core features for enterprise architecture with the ability to draw diagrams, manage objects and relationships aided by matrices and lists all stored in database. The database can be from one of many mainstream vendors such as MS Access, MS SQL, Oracle etc. Sparx EA also has a very rich document generation ability too. It can be configured and customised and its use is only limited by your imagination. Yes it very feature rich and so the learning curve can be very steep and a bit overwhelming to the inexperienced.
So first of all if you want to use Sparx EA to store and manage Enterprise Architecture of a business you need two things. An expert in Enterprise Architecture and an expert in Sparx EA. They could be the same person or two individuals. If you are lacking these then start looking as trying to learn both is probably a learning curve most mortals would find hard to climb for the short duration of a project.
Second like any problem you need to break it down. Who needs to use the tool and for what purpose? A use case model can help. During this discovery phase you should ask what Enterprise Architecture Framework are you going to base your work upon?
TOGAF, DODAF, ArchiMate and Zachman to name but a few. Other questions to ask are what viewpoints and elements will the stakeholders need and what data should those elements have to be useful to the stakeholders. Then prototype each use case in the tool to see how you would do it.
For enterprise architecture work I use a customised version of ArchiMate MDG (added extra features and attributes to the elements) and follow the Archimate V3.01 standard along with TOGAF V9.1. I also use various books like Enterprise Architecture At Work by Marc Lankhorst et al to guide me.
I have a meta model based on ArchiMate that describes all the elements and relationships along with a catalogue of viewpoints mapped to stakeholders. I based my catalogue of view points on the TOGAF and ArchiMate List.
These all allow me to cover everything in the enterprise from strategy, motivations for change, current states of business, data, application and infrastructure as well as future states and roadmaps to guide the organisation there.
So to re-iterate if you don't have the knowledge and experience in both methodology and tool then you need to find someone to help in one or both of these areas otherwise you will be doomed to fail.
Finally from the words of Mark Twain - Apologies for writing such a long response for I did not have time to write a shorter one.
Hope that helps and good luck with your endeavour.
