In the page for the module, you simply need to call Settings["yourSetting"] to retrieve it.

Make sure that within the settings page code-behind, you have it similar to this (C#):

 public override void LoadSettings()
        {
            try
            {
                if (!IsPostBack)
                {
                    object setting = TabModuleSettings["YourSetting"];
                    if (setting != null)
                    {
                        string settingValue = setting.ToString();
                        txtYourSetting.Text = settingValue;
                    }

                }

             }
            catch (Exception ex)
            {
                Exceptions.ProcessModuleLoadException(this, ex);
            }

        }

 public override void UpdateSettings()
        {
            try
            {
                ModuleController controller = new ModuleController();
                controller.UpdateTabModuleSetting(this.TabModuleId, "txtYourSetting", txtYourSetting.Text);

            }
            catch (Exception ex)
            {
                Exceptions.ProcessModuleLoadException(this, ex);
            }
        }

Let me know if you need any more help.