Gordon Exall has linked to this very useful guide. As his post rather wryly suggests, lawyers risk learning quite a lot from it too!
The Judiciary have published a Handbook for Litigants in Person. It can be found here.
WHY YOU SHOULD READ IT
I suggest every litigator has a look at it.
1. You should ensure it is sent to every litigant in person you are against (it will save your client time, money and anguish in the long run).
2. Give it to every paralegal or newly qualified lawyer in the firm. It provides invaluable advice in relation to disclosure, drafting witness statements and every element of the litigation process. It is drafted by working judges and there is a wealth of experience behind it.
3. If you don’t read it the litigant in person may well be better informed than you are.