There are two main routes up Crib Goch from Pen y Pass, both of which are Grade 1 scrambles. These are the East Ridge and the North Ridge.
The overwhelming majority of people climbing Crib Goch use the East Ridge, and this is considered the ‘normal’ route, from the sign at Bwlch y Moch.
The North Ridge is more complicated to find, especially in bad weather, and involves more of a detour so it makes a longer journey. It is much less travelled for these reasons. It can be approached from Llanberis via Cwm Glas; or via a very faint and tricky path from Bwlch y Moch known as the Foxes’ Path. Good skills are needed to follow this. If it is your first attempt on Crib Goch the East Ridge is the better choice by far.
Of course, it is also possible to approach Crib Goch from the other direction and do it the opposite way to the majority.