Create Custom List, store information and display the information on web part

Question

Hi,
Working on a Custom visual web part in sharepoint 2010. Scenario is i would like to have two button on that web part, one is "I read it " button for users to tag the page and another one is "find the list of people who already tag/read that
page". i have added a visual web part into my project and two buttons event within it. Now goal is once user click on "I read it button" it will create custom list to store urls and usersname. When click on "Find the list of people"
get the username only for that specific page whoever read/tag it.
1. How can i create the custom list to store all users information
2. Retrieve the information from Custom List and Display the list of people based on specific page url who ever read/tag that page. 
Any help will be greatly appreciated!

Answer 1

Appreciated for your help!
List has four columns Title, Hyperlink, Created by, and created. i just wanted to display Users and hyperlink column. i tried to retrieve the items from list but query is not returning any items and displaying. As you said in CAML query we can pass the page
url to get the collection of user for that particular page. but is not something will be hard coded value, if we pass the page url into CAML query? is there something we can dynamically retrieve the users based on page url.  for example, if users visits
30 different page url, i need to put all those urls into CAML Query. do i need to create custom user field or i can use Created by field to get the users? please correct me if i am wrong. Below is the code:
using System;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using Microsoft.SharePoint;
using Microsoft.SharePoint.WebControls;
using System.Data;
namespace CustomUserControl.VisualWebPart1
    public partial class VisualWebPart1UserControl : UserControl
        protected void Page_Load(object sender, EventArgs e)
        protected void btnRead_Click(object sender, EventArgs e)
            using (SPSite site = new SPSite(SPContext.Current.Web.Site.ID))
                using (SPWeb web = site.OpenWeb())
                    web.AllowUnsafeUpdates = true;
                    SPList list = web.Lists["UserInformation"];
                    SPListItem newItem = list.Items.Add();
                    SPFieldUrlValue hyper = new SPFieldUrlValue();
                    //hyper.Description = "Google";
                    hyper.Url = System.Web.HttpContext.Current.Request.Url.AbsoluteUri.ToString();
                    newItem["Hyperlink"] = hyper;
                    newItem.Update();
                    web.AllowUnsafeUpdates = false;
        protected void btnDisplay_Click(object sender, EventArgs e)
            SPWeb web = SPContext.Current.Web;
            SPList list = web.Lists["UserInformation"];
            SPQuery query = new SPQuery ();           
            query.Query = "<Where><Eq><FieldRef Name='Hyperlink' Type='URL' /><Value>http://nyc01d1sptmp01:8080/diligent/wiki/cft/Pages/home.aspx</Value></Eq></Where>";
            DataGrid grdList = new DataGrid();
            SPListItemCollection items = list.GetItems(query);
            DataTable table;
            table = new DataTable();
            table.Columns.Add("Title", typeof(string));
            table.Columns.Add("Hyperlink", typeof(string));
       table.Columns.Add("Created by", typeof(string));
            DataRow row;
            foreach (SPListItem result in items)
                row = table.Rows.Add();
                row["Title"] = result.Title;
                row["Hyperlink"] = result.Name;
       SPFieldUser userField = (SPFieldUser)result.Fields.GetField("Users");
                SPFieldUserValue userFieldValue = (SPFieldUserValue)userField.GetFieldValue(result["Users"].ToString());
                SPUser user = userFieldValue.User;
                string name = user.LoginName;
       row["Created by"] = name;
            grdList.DataSource = table.DefaultView;
            grdList.DataBind();