Apple, I am a mag so hope I can help a bit.... there are some inaccuracies in the advice here but generally speaking, Droitwichmummy has explained it well.
The next appointment with police will be for charge. The basis of the case against him will be given to his solicitor.He will then be police bailed to appear at his local magistrates court. If the value of goods stolen is less than around £5000 it is probable that magistrates would agree to hear the case. If the value is substantially more, or there are other factors which make the theft more serious then they are likely to refuse to hear the case and he will be committed to Crown Court for trial. If he pleads guilty at the first opportunity he is indeed entitled to a third off his sentence. The Magistrates in that case will either sentence him themselves or decide that the case is beyond their powers (maximum of 12 months custody on two charges of theft) and remit to the CC for sentencing.
The company's attitude to the theft has no influence over the police decision to charge, the prosecution or the sentencing so don't worry about that.
Basically what I am saying is that the value of the goods stolen is the first and biggest influence on whether his case is heard in the magistrates court or not. I have been involved in many similar theft by employee cases where we have been happy to keep it in the magistrates court. However, if the thefts went on over an extended period of time then that would make it more serious, as would the involvement of others.
Abandonment is not a relevant defence here, as his solicitor will explain to him. The fact that some of the items were being disposed of by the company does not mitigate the offence. Furthermore, the sentencing judge or magistrates will NOT take into account his loss of employment when sentencing him as it is not relevant.
I am really sorry, Apple, as a custodial sentence is a real option if this is at the higher end of the scale. If not, then a community order with significant hours of unpaid work is one alternative the court may consider. Please ask anything else if you need to and I will try and help.