The increasing amount of Nepali content on the web has opened doors for the research and development of a number of Natural Language Processing applications including Sentiment Analysis (SA). However, to best of our knowledge there has been no work in this area for Nepali language. In this paper we present two main approaches for sentiment detection of Nepali texts. We have developed Nepali Sentiment Corpus and Nepali SentiWordNet. In our first approach we develop a lexical resource called Bhavanakos, which is a Nepali SentiWordNet and implement a strategy in which sentiment words are detected in Nepali texts to detect the sentiment in documents. The second of our approach we train a machine learning based text classifier with annotated Nepali text data to classify the document.