This is a post for the newbies here who are scared of losing money on or immediately after the 1st of August due to UASF.
For those of us who know what UASF is and how it works, we have plans about what to do and will do it. This might be for example selling off our coins on the legacy chain and buying more on the new chain (this is what I'll be doing), or vice-versa (although vice-versa would seem extremely stupid to me as the risk of losing it all by having the chain wiped out is very high, it's something someone might choose to do).
For those of you who don't really get it though and don't really want to learn all about it, the simple advice is to do nothing. This means that you should not make any bitcoin transactions during this time. If you expect someone to send you BTC for whatever reason, ask them to do so before the 1st of August or to wait until a clear resolution (probably only a few days, but theoretically could be longer).
Watching this sub will help you figure out whether (and in which way) the situation has resolved. There will be posts either talking about the legacy chain being reorganised in to the new chain, which means that the UASF succeeded and there is now only one chain; or there will be posts talking about how there are now two chains with the legacy chain activating a hard-fork to avoid being reorganised in to the UASF chain (technically in that case there are three chains for a brief period, but the real legacy one pre-hardfork would be reorganised in to the UASF chain once everyone else moved to the hardforked one, ending up with two chains that are now entirely independent).
The reorganisation of the legacy chain in to the UASF chain is a clear signal of the end of the period of uncertainty. Two continuing chains without someone hardforking however means that transactions on the legacy chain are always at risk of being wiped out by being reorganised in to the UASF chain at some point and therefore uncertainty continues to exist. This is why eventually a hardfork would occur (probably based around the SegWit-on-bit4/2MB idea) on the legacy chain and it would then be safe from reorganisation.
All bitcoins you have currently will continue to hold value and can not be 'lost' if you never transact them during the chain split. In the first case – where the legacy chain reorganised in to the UASF chain – your coins will be valid on this new chain and you can transact them with confidence. In the second case – where a hardfork occurred and there are now two chains forevermore – the coins you hold will exist on both chains and can be transacted independently on both. Instructions will likely be clearly available on this subreddit about how to make sure you can indeed use them on both instead of only one.
As one exception: If an exchange or other online wallet where you do not have custody of the keys is holding your coins, then its entirely up to them whether you lose them or not or which chain they can be transacted on in the case of a split. While I think every major player will do their best to ensure you keep them and can transact them on both chains, there is no guarantee of this. If you have a significant amount of money there, you should move them to a system where you control the keys instead such as a wallet on your computer or smartphone/tablet (with appropriate backup and security precautions) or a hardware wallet device (much much safer). It's worth pointing out that this advice is generally true at all times even without the UASF or other forks.
All of the above said, I strongly recommend reading up more about the technology and proposals and then taking an active role instead. The greater the number of individuals involved actively in the future of bitcoin, the better it will be since you are not letting others choose and speak on your behalf (this is the main point of decentralisation as a general concept, which is a key aspect of bitcoin).
TL/DR: If you don't understand what's going on and don't want to learn, just avoid sending or receiving coins after 2017-07-31 until it's all over. They'll be safe.