Sharepoint Job... accessing and reading a list

SPWebApplication webApp = this.WebApplication;
SPSite site = this.WebApplication.Sites["SiteName"];
SPWeb web = site.OpenWeb("webUrl");  //  or site.RootWeb;
SPList list = web.Lists["ListName"];

foreach (SPListItem item in list.Items)
{
    //  If you know what fields you want, you can try the below
    object fieldValue = item["FieldName"];

    //  If you want to loop over all fields of an item
    foreach (SPField field in item.Fields)
    {
        object fieldValue2 = item[field.Id];

        //  Do whatever you want with field values
    }
}