The debate about whether it is good to be using voting bots or not is one that will never go away on the blockchain. My postion on it is to use it responsibly. I use voting bot especially my first month on steemit, it did helped spice up my blog a bit because it is not always nice seeing 0 cents under your properly researched and written blog posts. Apart from the 'decorative or look good' effect the upvotes have on my posts, It is one of ways to increase Steem Power. For every upvote you get from a bot, a part is automatically converted to SP during payout.
In this #minnowsbible edition, I will recommend a bot to use that you will never lose with. Then another tool to help you choose a profitable bot and profitable bid.
Remember for every your rewards on steemit, 25% goes to curators. Always put that into consideration when bidding and calculating the upvotes you get from these bots.
As a minnow, I will recommend you make minnowbooster your top choice. Unlike other bots that you bid on and your return on investment will return negative after deducting 25% curation. Minnowbooster is automated to reject and return your SBD for every bid you sent that will give negative ROI, wrong memo or post older than 5 days.
One thing is certain, you don't lose with minnowbooster. The only downside of minnowbooster currently is a bid of more 1 SBD rarely get accepted.
To get an upvote from minnowbooster, send an amount of SBD to minnowbooster from your wallet. Then copy and paste the link of the post you are boosting into the memo. You will receive an upvote in less than 2 minutes if your bid was successful. There are other services like delegating your SP to the bot or to other users for stwem/SBD and also leasing Steem Power from the delegation market. Sign up at minnowbooster.net with your steemconnect account to use these services.
Again, there are many other voting bots on steemit. The problem is it is hard to know which is profitable at a particular time and which amount will be profitable to bid. That problem was solved by steembottracker.com by 
Different factors like the vote value of each bot, minimum bid required, ROI limit, maximum age of your post, total bid put in already, maximum suggested bid by steembottracker and so on are clearly shown on the website.
The website highlights bots that are currently profitable and mostly in the last few minutes in green.
Visit the website and explore it to have better understanding of how it works.
Though it is your SBD to spend as you like but bidding 30 SBD for an upvote from a bot with $50 worth of upvote in the name of getting to the trending page is overdoing it.
Also you are at risk of getting a visit the grumpy cat if you boosted a post more than 3.5 days hugely.
So you can use voting bots to boost your and reward and reputation as there is no rule against it, i will only advise you do it with moderation.
Thank you for reading.
Please remember to upvote, resteem and leave a comment to share your thought.