In general a permissive signal will have a small black sign on the post. Type 05s are permissive signals.
Your signals you used are:
Type 02 - Diverging Signal
Type 05 - Permissive.
When you have a junction, you need to put in an absolute or Type 04 on the two tracks coming together to keep the trains from running through the junction. You can use one on a lesser busy track and keep the mainline unsignaled at that point if you wish.
Here's a quick guide to signal types:
Type 02/06 - Diverging Signal
Type 03 - Advance
Type 04 - Absolute
Type 05 - Permissive
Type 01/08 - Interlocking
Where the numbers are separated with a slash, it depends upon whether you are using the built-in, left side, or those by Jointed Rail, which I highly recommend.
Here's my signaling guide which works pretty well most of the time. Sorry for the bad drawing; I never said I was a graphic artist and Paint works very well for stuff like this, though drawing in Paint is like drawing with a fat crayon in kindergarten.
The black inverted T's are the bases of the signals and the lights face you if you are on the ground looking at them....
