road adding to a shapefile

hi, I am new on this group and i have some problems relative to my final year project. I have to realise a navigation system that rely on landmarks for a city of my country. A requirement is that i should not use google maps. I should use an osm map but those map are very poor for my country. Instead of it, I have an autocad file (.dwg) of the area that i want to cover. It would be i hope a good contribution for the projet. Then I know that :

1. I have to convert the map from dwg format into shapefile (I have done this whith autocad map 3d)
2. Use that shapefile on a map server that I have to deploy.(I have install geoserver)
3. I have to add a layer road, and landmark layer to that shapefile for navigation task.

My problem is now that i dont known how i could do the 3rd step.

Your help and suggest will be very helpful for me because it's the first time i have to deal with SIG. Best regard