Newbies advise for writing a eBook on IM

I don't think newbies should write ebooks on IM.

That would be my first advice.

I assume you mean you are writing FOR newbies, not that you are one. The list is really long but here are a few things that apply to me at least:

B2B
1. Focus on building relationships with established leaders in your industry. Getting nods from them helps you cement your own authority in your niche. Network with them via social media, their blog comments, etc. Try to guest post for them on their blogs.

2. Focus on building your mailing list. Offer a valuable freebie to encourage sign ups. Offer your list subscribers legitimate value in addition to what you are trying to sell them.

B2C
1. Online publicity is hugely important. Getting a recommendation from established media can have a huge impact on sales and brand awareness.

2. Determine whether you are selling a product that lends itself to a transactional model (i.e. one time purchases from customers) or a relationship-based business model and market accordingly. Don't waste your time with transaction-oriented techniques if your product requires rapport with customers. Don't waste time with customer retention efforts if you are selling the kind of thing that lends itself to single purchases.