Timeline up to The Sarah Connor Chronicles

Timeline A
1995
Derek Reese is born.

2002
Kyle Reese is born.

Unknown
Skynet goes online and declares nuclear war.
John Connor becomes the leader of the Resistance.

Unknown (much later)
“The Engineer” is sent back to 1963 to build a TDE and an isotope weapon and store them within a bank vault.

The story continues in Timeline B in 1963.
Timeline B
March 7, 1963 (or before December 31, 1963)

“The Engineer” arrives and builds a bank vault intended for storage of a TDE and a disassembled isotope weapon.

1995
Derek Reese is born.

Unknown/before September 10 1999
“The Engineer” succesfully builds and stores a TDE within the bank vault.
“The Engineer” succesfully builds and stores an isotope weapon within the bank vault.

2002
Kyle Reese is born.

April 19, 2011
Skynet are activated and becomes self aware.

April 21, 2011
20:11:00 Skynet starts nuclear war.

Unknown (before 2027)
“The Engineer” is sent back to 1963 to build a TDE and an energy weapon and store them within a bank vault.

Unknown
Skynet sends a terminator T-888 (known as “Cromartie”) back to 1999 to kill John Connor.

2027
The Resistance sends a terminator (later known as Cameron Phillips) back to 1999 to protect John Connor.

2029
Skynet decides to send a terminator T-800 back in time to kill Sarah.
John Connor decides to send back Kyle Reese, to protect Sarah.
John Connor manages to reprogram a T-800 and decides to send it back to protect his younger self in 1995.
Skynet decides to send a terminator T-1000 back in time to kill John Connor.

The story continues in Timeline C in the Sarah Connor Chronicles-timeline in 1999.