Mysql – Database design help needed

admin and active is just a bunch of 0's and 1's so can I do something like this? Since there will be 99% active and only a couple that will be inactive.

admin - id, user_id
inactive - id, user_id
social - id, user_id
facebook_link, twitter_link
member_forgot - id, user_id, forgot_code

Actually no, I wouldn't do this and keep it in the same table. The flag should be enough to distinguish between these two. The only difference in your queries is a active = true. Personally, I wouldn't consider this a bad design choice (altough your idea is not wrong, I would not use it in this case with - I'm guessing - a small set of data). Since only on set of data belongs to a single user, JOINs would make not that much sense.

I really want to practice splitting it up in different tables even if it is not a huge database, or is that a bad idea? So if I delete a user from the users table, it will delete all of the other records in the other tables associated with that user_id?

Again, I wouldn't do that personally(!). I don't see a benefit of seperating user centric data from the user. If you fear losing the data on deletion, introduce a deleted flag. This way, you will never lose data and your application just respects the deleted flag in your queries (this would also apply if you split the data accross tables).

Credit_Cards = 1110 format (visa, mastercard, discover, amex)

Storing credit cards is always very sensitive, according to PCI (as far as i remember) you are not allowed to store the CVV code (hope someone can correct me on that). But since this seems to be a fictional application, that should not be a problem.

You could always do something like this:

Create a users table to store all of your user info:

create table users
(
  id int, 
  user_name varchar(50)
);

insert into users values
(1, 'John'),
(2, 'Jill'),
(3, 'Bob'),
(4, 'Sam');

You state that you might need to apply this type of tracking for multiple applications. So you can create an application table to store the app name and any details.

create table applications 
(
  id int, 
  app_name varchar(50)
);

insert into applications values
(1, 'App 1'),
(2, 'App 2'),
(3, 'App 3');

Next create a categories table to store the info on each of the categories that you want to track by the users. This table will include a column that will contain the application id. This table will contain a foreign key relationship to the applications table. This allows you to have some flexibility in having the same category in multiple apps.

create table categories 
(
  id int,  
  cat_name varchar(100),
  a_id int 
);

insert into categories values
(1, 'Cat 1', 1),
(2, 'Cat 2', 1),
(3, 'Cat 3', 2),
(4, 'Cat 4', 3);

Finally, create the users_categories table which will contain the stats that you want to track, including user, category and then the action_date (the date the event took place).

create table users_categories
(
  u_id int,
  c_id int,
  action_date datetime
);
insert into users_categories values
(1, 1, current_timestamp()),
(2, 3, '2012-01-15 10:15'),
(3, 4, '2012-08-24 12:48'),
(1, 2, '2012-06-08 08:50');

Then to query the data, you would use something similar to this:

select *
from users u
left join users_categories uc
  on u.id = uc.u_id
left join categories c
  on uc.c_id = c.id
left join applications a
  on c.a_id = a.id

And the results would contain (See SQL Fiddle with Demo):

ID | USER_NAME | U_ID   | C_ID   | ACTION_DATE           | CAT_NAME | A_ID    | APP_NAME
------------------------------------------------------------------------------------------
1  | John      | 1      | 1      | '2012-09-28 06:47:53' | Cat 1    | 1       | App 1
1  | John      | 1      | 2      | '2012-06-08 08:50:00' | Cat 2    | 1       | App 1
2  | Jill      | 2      | 3      | '2012-01-15 10:15:00' | Cat 3    | 2       | App 2
3  | Bob       | 3      | 4      | '2012-08-24 12:48:00' | Cat 4    | 3       | App 3
4  | Sam       | (null) | (null) | (null)                | (null)   | (null)  | (null)

A few other suggestions, you could technically remove the a_id from the categories table and create a join table between categories and applications, similar to this:

create table categories_applications
(
  c_id int,
  a_id int
);
insert into categories_applications values
(1, 1),
(2, 3),
(3, 1),
(1, 2);

This would lead to one additional join in your queries, but the results would be the same:

select *
from users u
left join users_categories uc
  on u.id = uc.u_id
left join categories c
  on uc.c_id = c.id
left join categories_applications ca
  on c.id = ca.c_id
left join applications a
  on ca.a_id = a.id