You want something like:
/mnt/mySharedDrive 192.168.1.0/24(sync,no_subtree_check)
In the example, the drive mounted at /mnt/mySharedDrive is shared with any device on the 192.168.1.x subnet. Access will be read-only by default. For other sharing options refer to linux documentation for exportfs. I think the default is root_squash, sync minimises issues if disconnected but, yes, is slower if writing and no_subtree_check should speed things up, as I understand it.
I actually use no_root_squash beacuse I keep system backups on that nfs share which needs root permissions.