The National Archives at Kew (formerly the Public Record Office PRO in Chancery Lane, London) is where you can find court rolls and surviving court documents up till the early (20th.
There is a programme to digitise the surviving court records see the link AALT below
Pleas were made in Latin. They were recorded on membranes ( roughly 23 cm wide and 80 cm long) which were then stitched together. They were recorded term by term - four legal terms per year. If the term was a busy one then it leaves behind a very hefty pad!
In the England the latter is the work of the Selden Society. Although they have not (yet) looked at witchcraft/sorcery/occultism as a theme, but cases are caught in their wider net.
For example, SS v 82 Select cases in the Court of King's Bench under Edward III (1965) includes the trial of John Crok or KB27/ 443m 23d Rex to cite the court roll reference.
The records starts with the writ to the local bailiffs (who have Crok in custody) to bring him to court. Then there is a writ to another official to bring to court the bag containing Crok's paraphenalia (a book, the head of a dead man, and some mysterious marks on bits of paper). Both are dated 4 October.
Next there is the record of the trial itself - on Wednesday 8 October 1371.
John Crok appears in Religion & the decline of magic as a rare surviving example of a sorcery trial in the royal courts.
Latin (in a post-classical form) was the usual language of writs and court rolls until 1731 (4 Geo. II, c.26).