Gus' knees aren't jointed . . . Noob question

So, I am a noob to blender and its a sweet program. I have been working on gus for almost a day because of little misunderstandings( or whatever ) with the tutorial.

My Noob Question has to do with Bones and Joints, like Gus’ knee for example.

It says to just make a bone for his left leg then the new bone that suddenly appears should make the lower half of it. Making a complete leg with a knee joint. But I’m using 2.4 and it didn’t do this for me. I had to make another bone and assume it would be connected. I saw something in one post about selecting the first bone and then the next. Then Press ctrl-J and join them. I tried but it didn’t work when I went to pose him. (I hope I’m making sense) I feel kinda dumb because it’s probably really simple to do.

I can’t figure it out though. Thanks for any help.

Are there a lot of changes in 2.4 that will make older tutorials difficult?

I’ll probably have a lot more questions down the road but I guess that I’m in the right place.

Select the Tip of the Thigh-Bone in Edit mode and use E to Extrude the Shin bone and E again to extrude the foot bone.

Yes, there are many changes, especially in the Armature and how it’s rigged, but not so difficult as to make it impossible to know what question to ask.