The cable for network card comes in two types. One with Shilded pair type cable with BNC pins. These are common cables found to connect two or more Win9x machines with lesser efforts and easy installations with BNC type Ethernet cards.
And another most faster in data-transfer is RJ45 type cable with eight (8) cores of wires with RJ45 pins. We are talking about this second type of Network cable. The pins on RJ45 are counted as follows.

IMP NOTE: The new Ethernet Card with both types of connectors, i.e., BNC and RJ45 is called combo-card. The Ethernet cards come with SETUP-DISK which helps you to toggle between the BNC and RJ45 interface setting. Old ethernet cards came with jumpers to do this task, but nowadays, the jumperless Ethernet Cards are needed to be set to RJ45 or BNC type through the SETUP program disk given with it. These SETUP programs do write on the NVRAM chip on the card. Read the README.TXT of such SETUP-DISKS or Card's MANUAL for more information. Also most important thing to keep in mind is that you need to setup the card with free I/O-port and free IRQ number of your system which are assigned to the card through that SETUP program of the card. For example, TYPE:RJ45, PORT:320, IRQ:10, etc. Please do not ask me further about this that I may not answer in this section further even though I do setup these cards perfectly everytime. Actually this needs more practical experience than theory. You may find the appropriate sites elsewhere on this subject on Internet.

The pinout I am giving is not any special kind but simply a straight parallel pins cable to connect any network system in FEMALE SOCKET of the NETWORK HUB. With compatible softwares this cable is both for 10Base-T and 100Base-TX cards. In simple words the MALE RJ45 PIN is inserted directly into Ethernet Cards of a a Network Computer which may be either a SERVER of a WORKSTATION to the NETWORK HUB.

NOTE: Remember pin 1 and 2 are on one color pair. 3 and 6 are on second color pair of wire. These colors are technically approved and standardized set for straight RJ45 cat5 cable. But the color codes of the wires become irrelevant when you connect right number pin to right wire from pin to pin. Also its not guaranteed that you will get the perfect colored cores of cable in your city/area. Anyway this is straight cable, so no need to think much about it. Connect all pins straight with crimping tool even though the descriptions for some pins are not given as they are not used for common data transfer but for some other internal signaling. Believe me its not worth knowing for or may be I don't know. ;-)

To avoid the expensive hub unit when only two systems are to be connected to each other directly at Ethernet Cards with this cable called Crossover Cable. With compatible softwares this cable is both for 10Base-T and 100Base-TX cards. This MALE RJ45 PIN is inserted directly into Ethernet Cards of both the Machines.

100Base-Tx uses 4 wires (2pairs) to transmit data against the 100Base-T4 cable which uses all 8 wires (8pairs). Etherenet 100Base T4 is generally works at nearly 100mbps with standard 100mbps HUB.  But it works at nearly 200mbps with Network Switch (Extended Version of HUB).

This is slightly different from 10/100Base-T Crossover cable as 100Base-T4 is for 100MBPS Ethernet cards which avoids the expensive hub unit when only two network systems are to be connected to each other. The systems can be connected to each other directly at 100MBPS Ethernet Cards with this cable called 100Base-T4 Crossover Cable. The MALE RJ45 PIN is inserted directly into Ethernet Cards of both the Machines.  

100Base-T4 uses all eight wires (4pairs) to transmit data against the 100Base-TX cable which uses only 4 wires (2pairs).  Etherenet 100Base T4 is generally works at nearly 100mbps with standard 100mbps HUB.  But it works at nearly 200mbps with Network Switch (Extended Version of HUB).

Sometimes, I myself made mistakes while making this cable because all pins are very important to crossover.  But you don't have to do any mistake here. 
Let me put it more easy way with pins in serial order of two ends of same cable.  This is applicable to both (10Base and 100Base) crossover cables given on this page. Now, with this diagram, it is more easy to make crossover cable. Phew.

6. HOW TO MAKE ABOVE NETWORK CABLE?
RJ45 jacks are to be made with special RJ45 cable with EIGHT cores of wires, RJ45 pins and cable must be connected with a RJ45 cable Crimping Tool available at any leading electronic shops. If totally unaware of crimping method, you may need to get some help from cable crimping specialists. I can suggest you another way out. Buy some old RJ45 nornal (straight) cable and cut it in the middle. Separate the core-wires of the cable. Solder them as per pinouts required and tape them properly. That's all. Now I need some appreciation from you. Isn't it? ;-)