I wonder why your customers are asking for a manual or product guide. So, here are a few strategies to deal with that, depending on the reason for the requests.
First, your customers may really need a manual. This may be due to the following reasons:
- Your product is complex by nature. Think software libraries or dedicated applications such as Photoshop.
- Your product is used by many different employees. Training is expensive and they may want to do it in-house.
- Your support option are seen as too expensive, so your customers like to avoid them.
Then, at least an online manual is useful. Maybe, FAQs or similar would also do the job.
Second, the requests for a manual may just be a sign of your customers mistrust or fear; your prospects could have problems judgeing the value of your product. This may be due to the following reasons:
- Your sales presentation (or web site) lacks certain information needed to trust you as a supplier.
- Your product requires large additional upfront investments. Think ERP software, for example.
- Your product is central to your customer's business, so the really want to make sure it's complete.
- The decision makers are incapable to make a judgement; maybe, because they're not the final users.
In this case, your manual is technically not really needed. It just serves as a signal of your commitment and the (hidden) quality of your product. But having one could raise sales. If such a case, here's a tip: The more expensive and throughout it looks, the better.
However, you may also use other means to signal your commitment. The look and the amount of your advertising and sales material are possible options: Better web page design, high-end advertising, display of other companies' trust in your product, etc.
Third, the request may just be an adhoc objection, raised to find any reasons to not buy right now. Then, you would only get these requests during sales meetings. The best response would probably to ask, why they would need such a manual; followed by reasons why they wouldn't really need it, since your product is designed to be useable, requires no training or manual, etc. etc.
Hope this helps.