congratulations for your offer! As mentioned, you will get a lot of training on both at the beginning; Vlad mentioned some additional good resources. In terms of Excel, I would just add one tip – try to master VLookUp and Pivot Tables – they will be some of the main tools you would use.
If you want to properly prepare, I would not consider technical skills only though. Consulting is a people business and can be highly stressful time to time, thus, would be equivalent important to prepare on:
- Communication and people skills: a classic on the topic is the book “How to win friends and influence people” by Dale Carnegie. If you can have any kind of sales experience before that would also help a lot (a lot more than reading-only)
- Stress management. I recommend “The Secret” by Rhonda Byrne.
For the long term these skills are actually more important then the technical ones.
A couple of things that could help you during your first weeks are instead the following:
- Take notes when your manager tells you something – this will help you to remember details and will show you care about them to the team.
- Align frequently with your manager on priorities and deadlines. Chances are you will always have too many things to do. Either you learn which things go first or you will risk to sleep very few hours in your first weeks ;)
- Ask for feedback every two-three weeks – this will show you are proactive and willing to learn.
- Always double check. First impression is very important in consulting: if you show you are reliable from the beginning, you will create a reputation of a reliable person.
- Ask for help when you don't know what to do – better to let know you are in trouble with meeting a deadline then missing the deadline.
- Be social and respectful with the support staff – these people are great and influential as well in the company.
- Start to build a weekly calendar the Sunday before. Allocate main tasks, both for private life and work. Will be though to do at the beginning but once you master this skill your productivity will skyrocket, as will force to think about your priorities a lot in advance.
Hope this helps,